ASAHI KASEI [AK4571] AK4571 USB Interface Audio CODEC Features: USB Audio Controller 12 Mbps bit rate USB Serial Interface Engine (SIE) Audio Class Processing Block 4 Endpoints USB transceiver General Description: The AK4571 is a USB Interface audio CODEC. The AK4571 incorporates a 16-bit CODEC, PLLs, USB transceiver, SIE (serial interface engine), audio class processing unit, FIFO and other required signals into a single chip. The AK4571 can simultaneously transmit and receive audio stream data through USB bus. In addition to this, the single-channel ADC and 2channel DAC can operate at different sampling rates. 16bit CODEC - Single-channel A/D Converter Microphone Pre-Amp (Fixed Gain: 20dB) Mute/Volume Control Programmable Gain Control +24dB to -31dB ( 1dB step ) - D/A Converter 2 channels - Mixer Mute/Attenuation Control +0dB to -47dB ( 1dB step ) Analog Bass Boost The AK4571 has a programmable gain amplifier for analog input (IPGA). The gain range is from -31dB to +24dB with 1dB steps. In addition to the IPGA, the AK4571 also has a fixed +20dB pre-amplifier. Analog input signals can be mixed directly with the D/A signal and sent to the LINEOUT pins of the chip. The analog outputs of the AK4571 can be attenuated up to -47dB in 1dB steps. The AK4571 also has an analog bass boost circuit. Bass Boost response can be modified by changing the values of external resistors and capacitors. The AK4571 has a Human Interface Device function that allows a user to control the playback volume at the device side. The playback volume on mixer applet moves up or down automatically by the operation of HID buttons. The AK4571 also can mute analog input signal locally in addition to mixer applet control. HID Support remote control of playback volume/mute recording mute/status function Power Management control of external headphone amplifier low power at suspend mode (< 1uA) The AK4571 has advanced power management capabilities. Suspend current is less than 1uA. The AK4571 can also control the power of an external headphone amplifier to conform to the USB suspend current requirement of 500uA maximum. EEPROM Interface (Microwire Interface) - can read Device/String Descriptor from EEPROM - 1K/2K/4K bit EEPROM The AK4571 has a Microwire interface for an external EEPROM, allowing customization of Vendor ID and product ID. On-chip PLL 7 sampling frequencies: 8kHz, 11.025kHz, 16kHz, 22.05kHz, 32kHz, 44.1kHz, 48kHz The high integration of the AK4571 reduces both the number of external components required and the PCB area required to build USB devices, including small format products such as USB headsets. Single Power Supply, Low Power +3.3Volts0.3V Package 48pin LQFP MS0153-E-03 2005/06 -1- ASAHI KASEI [AK4571] Block Diagram VA AGND BGND STBY CS RBFI M M Bass Boost Bass Boost EPDO EPAI SK EPEN EEPROM I/F Power Management EPSW EMSW RBFO LOUT INC VREF MICBIAS ROUT VRAD VRDA MSTAT IMUTE OMUTE DEC DGND VD VCOM Config ROM Master volume Mixer ATT ATT DAC String ROM FIFO DAC EPSEL FIFO Audio Control Block USB Serial Interface Engine USB Transceiver DP DN LBFI LBFO GAIN MICIN 20dB M ADC GAIN AMP1O AMP2I M FIFO PLL AMP2O LFLT_44K LFLT_48K LFLT_SYS XTLIN PLL1 XTLOUT RSTN CRYSTAL MS0153-E-03 2005/06 -2- ASAHI KASEI [AK4571] Ordering Guide AK4571VQ AKD4571 0 +70C 48pinLQFP(0.5mm pitch) Evaluation Board for AK4571 Pin Layout 40 EPSEL 35 DGND BGND XTALOUT XTALIN TEST2 45 1 TEST1 IMUTE MSTAT INC DEC OMUTE RSTN SUSN DP DN TEST3 VD EPDI EPAO SK 5 CS EPSW STBY 30 EMSW LFLT_SYS LFLT_44K LFLT_48K VCOM EPEN TESTMODE3 TESTMODE2 VRDA 10 VRAD 25 20 15 ROUT RBFO RBFI LOUT LBFO LBFI TESTMODE1 AMP2O AMP2I AMP1O MICIN MICBIAS MS0153-E-03 AGND VA 2005/06 -3- ASAHI KASEI [AK4571] Pin/Function No. Signal Name USB Interface 46 DP I/O Ana / Dig I/O D USB bus Non-Inverting pin. Since the AK4571 is a full-speed device, a 1.5k resistor must be connected between D+ node to VD. 47 DN Reset, Crystal, PLL 45 RSTN I/O D USB bus Inverting Pin. I D Reset Pin. Low input resets the chip. Schmitt Trigger input. Suspend Pin "L": Suspend Mode "H": Normal Mode Crystal Oscillator Output, Connect Crystal Resonator. Connect capacitor Crystal Oscillator Input, Connect Crystal Resonator. Connect capacitor System PLL loop filter Pin. Connect 2.7k resistor and 22nF capacitor in series externally. Codec PLL loop filter Pin. Connect 120k resistor and 6.8nF capacitor in series externally. Codec PLL loop filter Pin. Connect 120k resistor and 6.8nF capacitor in series externally. 44 SUSN O D 4 5 9 XTALOUT XTALIN LFLT_SYS O I O A A A 10 LFLT_44K O A 11 LFLT_48K O A O O O I O I O A A A A A A A O O I O I O O A A A A A A A Analog Input/Output 12 VCOM 27 VRAD 28 VRDA 14 MICIN 15 AMP1O 16 AMP2I 17 AMP2O 21 24 19 20 22 23 13 LOUT ROUT LBFI LBFO RBFI RBFO MICBIAS External Headphone Amplifier Control 6 EPSW O 7 STBY O 8 EMSW O Description Analog Common Voltage Reference Pin ADC Common Voltage Reference Pin. ADC Common Voltage Reference Pin. Mono Channel Microphone Input Mono Channel 1st Amplifier Output Pin Mono Channel 2nd Amplifier Input Pin Mono Channel 2nd Amplifier Output Pin Please Connect 1nF capacitor. Left Channel D/A Out Right Channel D/A Out Left Channel Bass Boost Filter Input Pin Left Channel Bass Boost Filter Output Pin Right Channel Bass Boost Filter Input Pin Right Channel Bass Boost Filter Input Pin Voltage Reference Output for the Microphone's bias voltage When the chip goes into Suspend mode, this pin goes to Hi-Z. External Headphone Amplifier Power Switch Control Pin 1 "H": Normal Operation "L": Suspend Mode External Headphone Amplifier Power Switch Control Pin 2 "L": Normal Operation "H": Suspend Mode External Headphone Amplifier Mute Control Pin "H": MUTE ON "L": MUTE OFF MS0153-E-03 2005/06 -4- ASAHI KASEI [AK4571] No. Signal Name EEPROM I/F I/O Ana / Dig Description 31 CS O D EEPROM I/F Chip Select Pin 32 SK O D Read Clock Pin 34 EPDI I D EEPROM Data Input Pin 33 EPAO O D EEPROM Address Output Pin 35 EPEN I D 36 EPSEL I D EEPROM Enable Pin "H": Read Device/String Descriptor from external EEPROM "L": Read Device/String Descriptor from internal ROM. CS,SK,EPDI,EPAO are Hi-Z EEPROM Select "L": 1Kbit Type EEPROM is connected. "H": 2Kbit/4Kbit EEPROM is connected HID Interface 39 IMUTE I D 43 OMUTE I D 41 INC I D 42 DEC I D 40 MSTAT O D P P P P P A A D D D Power Supply 25 VA 26 AGND 1 VD 2 DGND 3 BGND Test Mode 18 TESTMODE1 29 TESTMODE2 30 TESTMODE3 38 TEST1 I I I I A/D Mute Toggles mute status at the rising edge. If this pin is not used, please connect this pin to DGND. D/A Mute Sets "1" to internal register at the rising edge, and reset to "0" at the falling edge. If this pin is not used, please connect this pin to DGND. D/A Volume Up Pin Sets "1" to internal register at the rising edge, and reset to "0" at the falling edge. If this pin is not used, please connect this pin to DGND. D/A Volume Down Pin Sets "1" to internal register at the rising edge, and reset to "0" at the falling edge. If this pin is not used, please connect this pin to DGND. Recording Mute Status Pin. "H": Mute ON "L": Mute OFF In suspend mode, this pin is "L". Analog Power Supply, 3.3V Analog Ground Digital Power Supply, 3.3V Digital Ground Bulk Ground, 0V Please tie down to AGND for normal operation. Please tie down to AGND for normal operation. Please tie down to AGND for normal operation. Please tie down to DGND for normal operation. 37 TEST2 O Please open state 48 TEST3 I Please tie down to DGND for normal operation. MS0153-E-03 2005/06 -5- ASAHI KASEI [AK4571] Absolute Maximum Rating AGND, DGND=0V Parameter Power Supplies Analog Digital |DGND-AGND| Input Current (any pins except for supplies) Analog Input Voltage Digital Input Voltage Ambient Temperature Storage Temperature Note 1. All voltages with respect to ground Symbol min Max Units VA VD GND IIN VINA VIND Ta Tstg -0.3 -0.3 4.5 4.5 0.3 10 VA+0.3 VD+0.3 70 125 V V V mA V V C C -0.3 -0.3 0 -40 Warning: Operation at or beyond these limits may result in permanent damage to the device. Normal operation is not guaranteed at these extremes. Recommended Operating Condition AGND, DGND=0V Parameter Power Supplies Analog Digital Symbol min typ Max Units VA VD 3.0 3.0 3.3 3.3 3.6 3.6 V V All voltages with respect to ground. * AKM assumes no responsibility for usage beyond the conditions set forth in this datasheet. MS0153-E-03 2005/06 -6- ASAHI KASEI [AK4571] Analog Characteristics Ta=25C,VA=VD=3.3V, Signal Frequency=1kHz, Sampling Frequency Fs=44.1kHz BW=20Hz - 20kHz, TEST mode; unless otherwise specified Parameter Min typ Max Units Mono ADC (1 channel) Resolution 16 bits S/N (A weight) @44.1kHz 83 dBA (PGA is set to 0dB) AMP2I input : USB Normal mode S/(N+D) (-1.0dB analog input) USB Normal mode 73 dB Full scale input Voltage 0.53 0.6 0.67 Vrms MIC amplifier S/N (A weight) 76 84 dBA MICIN input AMP1O output Gain 20dB Selected +17 +20 +23 dB Input Impedance 10 20 k Stereo DAC (2 channel) Resolution 16 bits S/N (A weight) @44.1kHz (DAC volume &master volume is set to 0dB) 84 dBA USB Normal mode S/(N+D) (-1.0dB digital input) USB Normal mode 75 dB Full scale output Voltage 0.53 0.6 0.67 Vrms PGA Step size 0 1.0 2.0 dB Attenuation control range -31 +24 dB Input Impedance AMP2I input 10 20 k Master volume: step size 0 1.0 2.0 dB Attenuation control range -47 0 dB Output Load Resistance 10 k Output Load Capacitance 5 pF Bass Boost Internal Resistance 40 k External Resistance 360 400 k External Capacitance 5 pF MIC Bias (Buffer Amp) Output Voltage 1.94 2.2 2.46 Vdc Output Current 2 mA Power Supplies mA 52 35 Analog mA 23 15 Digital mA 75 50 Total uA 150 0 Power Down(Suspend) MS0153-E-03 2005/06 -7- ASAHI KASEI [AK4571] Filter Characteristics Ta=25C, VA=VD=3.3V, fs=44.1kHz Parameter ADC Digital Filter ( Decimation LPF) min typ 0 26.5 70 Pass band (0.2dB) Stop band Stop band Attenuation Group Delay ADC Digital Filter (HPF) max Units 17.64 kHz kHz dB ms 0.363 Frequency Response: -3dB -0.5dB -0.1dB DAC Digital Filter 6.89 19.3 44.9 0 26.5 70 Pass band (0.2dB) Stop band Stop band Attenuation Group Delay DAC Analog Post filter Hz 17.64 kHz kHz dB ms - dB 0.312 Pass band Frequency Response - MS0153-E-03 0.1 2005/06 -8- ASAHI KASEI [AK4571] Digital DC Characteristics Ta=0 - 70C; VD=3.0 - 3.6V; DGND=0V Measurement under static state All digital pins except DP, DN. Schmitt hysteresis level of RSTN pin and levels of all test pins will not be tested. Parameter Symbol Min Typ Max EPDI,EPEN, EPSEL, pin "H" level input voltage VIH 70%VD EPDI, EPEN, EPSEL pin "L" level input voltage VIL 30%VD RSTN pin "H" level voltage VIHR 2.4 RSTN pin "L" level voltage VILR 0.8 IMUTE, OMUTE, INC, DEC pin "H" level voltage VIHR 2.4 IMUTE, OMUTE, INC, DEC pin "L" level voltage VILR 0.8 SUSN, EPSW, STBY, EMSW, MSTAT pin VOH 2.4 "H" level output voltage IOH= 2mA SUSN, EPSW, STBY, EMSW, MSTAT pin VOL 0.6 "L" level output voltage IOL= -2mA CS, SK, EPAO pin "H" level output voltage VOH 2.4 IOH= 2mA CS, SK, EPAO pin "L" level output voltage VOL 0.6 IOL= -2mA DP, DN Single Ended Receiver Threshold for "H" level VIHR 2.0 DP, DN Single Ended Receiver Threshold for pin "L" level VILR 0.8 Input Leakage Current Iin 10 Rpd 100 Pull down Resistance (only EPDI pin)@3.3V Ta=25C Switching Characteristics Ta=25C, VA=VD=3.3V Parameter Symbol Min Typ Master Clock Frequency MCLK 12.000 Reset input width @RSTN pin(low active) Wrst 1.0 Time Width for USB Reset Signal Recognition Trst_rec 3.0 DP<VseL & DN< VseL to USB Reset mode Device Ready Time from USB Reset Tdrr After releasing from USB Reset to Device Ready (Transaction can start) Time Width for Suspend Recognition Idle state ( DP > VseL & DN < VseL ) Tsus_rec 4.36 to Suspend mode Resume Time from Suspend Tresm First flip of DP/DN from Idle state To Device Ready*) Imute input width with @IMUTE pin(High active) Wimute 10.005 Omute,Dec,Inc input width with @OMUTE,DEC,INC Wodi 2.001 pin (High active) Device Ready: VREF, X'tal oscillator and PLL are stable and standard bus transactions can proceed MS0153-E-03 Units V V V V V V V V V V V V A k Max - Units MHz us s 10 ms ms 30 ms ms ms 2005/06 -9- ASAHI KASEI [AK4571] Trst_rec Tdrr Tsus_rec Tresm resume time recovery time D+ D- Master Clock Figure 1. Mode Change with respect to Bus States Transmitter/Receiver Characteristics Ta=25C; VD=3.3V; DGND=0V; CL=50pF Parameter Symbol Transmitter Pins Data Rate DR DP,DN Output Impedance (Hi) Roh DP, DN Output Impedance (Lo) Rol DP, DP "H" level Output Voltage "L" level Output Voltage Tri-state Leakage Current Rise/Fall Time Rise/Fall Time Matching Crossover Point Receiver Vohd Vold Iolk Trf/Tff Trfm Vcrs DP, DN DP, DN DP, DN DP, DN DP, DN DP, DN Input Common Mode range Differential Input Level CMR Vdiff DP, DN DP, DN Conditions DP, DN="H" at Iout = -10mA DP, DN="L" at Iout = 10mA at Iout =-200uA at Iout =2.2mA 0 < DP, DN< 3.3V | DP - DN | MS0153-E-03 Min Typ Max Units 11.97 12 12.03 MHz 36 36 2.8 -10 4 0.8 0.2 10 100 1.65 0.3 10 20 2.5 V V A ns % V V V 2005/06 - 10 - ASAHI KASEI [AK4571] Trf Trs Tff Tfs 90%VD DP, DN 10%VD Figure 2. Rise/Fall Time Vcrs DP, DN Figure 3. Crossover Point MS0153-E-03 2005/06 - 11 - ASAHI KASEI [AK4571] 1 Device Overview 1.1 PLL and Sampling Rates The AK4571 has three PLLs in addition to a crystal oscillation circuit. The first PLL generates a system clock at 48MHz, the second PLL generates the clock for 44.1kHz sample rates (including derivatives of this sample rate) and third PLL generates the clock for 48kHz sample rates (including derivatives). The CODEC clocks are generated from the USB SOF, so they are synchronized with USB SOF. The ADC and DAC operate at one of seven sampling rates, 8kHz, 11.025kHz, 16kHz, 22.05kHz, 32kHz, 44.1kHz, and 48kHz. The ADC and DAC can operate at different sampling rates. 1.2 A/D Converter & D/A Converter The AK4571 has a 16-bit single-channel A/D converter, and a 16-bit two-channel D/A converter. The AK4571 has a programmable gain amplifier for the analog input (IPGA) with a range from -31dB to + 24dB in 1dB steps. In addition to the IPGA, the AK4571 has a fixed 20dB gain pre-amplifier. Therefore the total gain of the analog input is +44dB maximum. Analog output can be attenuated from 0dB to 47dB in 1dB steps. Analog input and the D/A signal can be mixed in the chip and sent to the Line outputs. The Lineout volume, the microphone playback volume, and the microphone recording volume can be controlled directly from the PC 1.3 Bass Boost Control The AK4571 has an analog bass boost circuit, and can boost the bass frequencies of the lineout signal by up to 20dB. Frequency response and DC gain are adjusted by external resistors and capacitors. The Bass boost effect is controlled via the HID application. 1.4 Serial Interface Engine (SIE) & Audio Class Processing Block The AK4571 has a Serial Interface Engine that processes lower-level protocols like CRC checking, bit stuffing, NRZI encoding/decoding, in addition to higher-level protocol like USB standard requests. SIE also notifies the backend that it has received an Audio Class Request, and passes the request to the backend. The backend decodes and processes Audio Class Request like mute requests, volume requests and sampling frequency control requests. Therefore, the AK4571 does not require a micro-controller for this processing. 1.5 HID (Human Interface Device) Since the AK4571 supports HID function, mute and volume can be controlled remotely. The host knows whether the playback volume/mute button has been pressed or not by issuing an Interrupt Request periodically, and notifies the application that the status has changed. The software application issues the volume/mute request in order to synchronize the software with the AK4571. Input/ Recording signals can be also muted independently of the software application. 1.6 EEPROM I/F The AK4571 has all of its descriptors in its internal ROM, so it does not require external an EEPROM. However vendor ID, vendor name, product ID, and product name can be also customized by using an external Microwire interface EEPROM. A MicrowireTM type, 1K, 2K, or 4K EEPROM can be used. MS0153-E-03 2005/06 - 12 - ASAHI KASEI [AK4571] 1.7 Power Management The AK4571 starts its transition to suspend mode when the idle state of USB bus continues more than 3ms. The AK4571 suppresses the power-supply current (typ.1uA) while in suspend mode because all blocks, including PLLs, pare placed in power-down mode. Under normal operation the AK4571 supplies a bias voltage via the output buffer to the microphone. In suspend mode, the MICBIAS pin goes to a Hi-Z state, and the AK4571 does not supplying this current to the microphone. The AK4571 also has 3 pins for control of an external headphone amplifier. These pins are used to suppress the power-supply current during suspend mode in addition to suppressing "pop noise" during the transition of suspend/resume. The AK4571 has two pins for power-control because there are "active high" types and "active low" types of external headphone amplifiers. Third pin is for the mute control to suppress transitional pop noise. The USB bus consumes 200uA current even in suspend mode. A regulator also consumes current in standby mode. Even with these devices consuming power the system can still conform to the 500uA USB specification because of the AK4571 low-power consumption and its control of the microphone and headphone power circuits. TheAK4571 is ready for operation 30ms after transitioning from suspend mode to normal operating mode. 1.8 USB Transceiver The AK4571 includes a USB transceiver. MS0153-E-03 2005/06 - 13 - ASAHI KASEI [AK4571] 2 2.1 Functional Description Synchronization of the host and the AK4571 The ADC and DAC in the AK4571 operate synchronously with the SOF (Start of frame) of the USB bus. USB's Isochronous transfer guarantees that audio stream data is transferred once per frame. However, USB does not specify the start point of the transfer in a frame. The worst-case period between two transfers is about 2ms.therefore the AK4571 has a FIFO that stores 2ms audio stream data. If the CODEC operates at 44.1kHz sampling frequency, the AK4571 expects that 45 samples are transferred once per10 frames. (Please see Figure 4) The average sampling frequency in Figure 4 is 44.1kHz. N Frame (N+1) Frame 44 samples 44 samples (N+9) Frame 45 samples (N+10) Frame 44 samples Figure 4 Synchronization Scheme The AK4571 transmits all A/D data stored to FIFO in the previous frame while updating the A/D data to FIFO in the current frame. The sample count of 48kHz series D/A data per frame is fixed in all frames. For 44.1kHz, the appearance of 45 samples should be just one time per 10 frames. If the D/A clock and SOF clock operated asynchronously, the FIFO would overrun or underrun, and an audible pop noise would occur periodically. Therefore, CODEC clocks are synchronized with SOF clock. In order to achieve this synchronization, the AK4571 has built-in two PLLs for CODEC clocks and generates clocks for both of 48kHz sample rate series and 44.1 sample rate series. 2.2 Power Management USB devices fall into one of three power categories: 1) Low-power Bus-powered Devices (<100mA) 2) High-power Bus-powered Devices(>100mA, <500mA) 3) Self-powered Devices. As the AK4571 is a low-power consumption device, it can be defined as a Low-power Bus-powered Device and can be connected to a bus-powered Hub. (High-power Bus-powered Devices can't be connected to a Bus-powered Hub) USB specifications require a maximum of 500uA in suspend mode. This includes the current drawn between Vbus and ground through the 1.5 k ohm resistor tied to D+ line and Vbus. This current is about 200uA. Two points should be considered in order to observe the USB suspend mode specification. a) Suppression of the AK4571 current All blocks including ADC, DAC, PLL go to power-down mode when the idle state continues for more than 3ms. Values like volume and mute status are preserved in suspend mode. b) Control of External Circuits The USB specification does not permit more than 500A of current in suspend mode. Therefore, the AK4571 must control the power dissipation of the external headphone amplifier and microphone. Since the MICBIAS pin is in a Hi-Z state in suspend mode, the AK4571 does not supply current to the microphone. Headphone Amplifiers commonly have power-down pin and can be controlled externally. There are two types of power-control logic; active-low and active-high. Some headphone amplifiers have a mute pin for suppressing pop noise. The AK4571 supports all of these headphone amplifiers. MS0153-E-03 2005/06 - 14 - ASAHI KASEI [AK4571] SOF SUS_N(internal) EMSW(Mute SW) STBY EPSW(STBY) 1.45ms 1.45ms Figure 5 Suspend and Resume Sequence MS0153-E-03 2005/06 - 15 - ASAHI KASEI [AK4571] 2.3 Bias Circuit for Microphone The AK4571 supplies a bias voltage to the microphone through the MICBIAS pin. The output voltage is about 2.2 volts and output current is 2mA maximum. Since the microphone's output signal level is very low, the noise level of the bias voltage should also be low. USB bus transactions typically cause variation of the regulator's output. However, the AK4571 has a built-in voltage reference for mic bias, and suppresses the bias noise caused by the regulator. Coupling capacitors should be connected in parallel between the two resistors (i.e. Ra=300, and Rb=4.7k/2.2k) in order to make the bias circuit stable. The appropriate value, Rb, depends on the microphone `s characteristics. The output is placed in a Hi-Z state in suspend mode. 2.4 EEPROM Interface The AK4571 has all descriptors, including String Descriptors, in its internal ROM so it does not require an external EEPROM. The AK4571 also has an EEPROM interface so that an external EEPROM can be attached for customizing Vendor ID, Product ID, vendor name and product name. The EPEN pin should be "L" if the EEPROM is not used. CS, SK, EPAO pins are at a Hi-Z state in this configuration. Please see "Descriptors in Detail" section for internal ROM information. The EPEN pin should be "H" if an external EEPROM is used. The AK4571 reads the Device Descriptor from the EEPROM after a USB Reset. The AK4571 starts to read String Descriptor just after receiving "GET Descriptor (String)" request. With the AK4571 you can customize the following fields: 1) Device Descriptor (18 bytes) 2) String Descriptor (Language ID, Manufacturer Name, Product Name) Microwire type (4 wire) , 1K/2K/4K bit EEPROM can be used (for example, AK93C45A/55A/65A) If a 1Kbit EEPROM is selected, the length of Manufacturer name or Product name should be just 50 bytes. As each String Descriptor requires 2-bytes of length information, the total length of each String Descriptor is 52 bytes. If a 2K/4K bit EEPROM is selected, the length of Manufacturer name or Product name should be just 100 bytes. As each String Descriptor requires 2-bytes of length information, the total length of each String Descriptor is 102 bytes. If a 1K bit EEPROM is used, EPSEL pin should be "L" while EPSEL pin should be "H" for a 2K/4K EEPROM. The length in both cases should be exactly 52 bytes or 102 bytes, no longer, no shorter. Table 1 shows the relationship between EEPROM address and Descriptor. Device Descriptor (18 bytes) String Descriptor Lang ID (4 bytes index = 0) String Descriptor iManufacturer (52 or 102 bytes: index =1) String Descriptor iProduct (52 or 102 bytes: index = 2) 1K bit EEPROM (AK93C45A) 00h -08h 09h -0Ah 0Bh-24h25h-3Eh 2K/4K bit EEPROM (AK93C55A/65A) 00h-08h 09h-0Ah 0Bh-3Dh 3Eh-71h Table 1 Relationship between EEPROM Address and Descriptor Since the AK4571 cannot write data to the EEPROM, the EEPROM should be mounted on the PCB after it has been programmed with the necessary data. Please refer to the AKM EEPROM datasheet for the write sequence. If EEPROM is not used (EPEN ="L"), an EEPROM should not be mounted on the PCB because the CS, CK and EPAO outputs are Hi-Z when EPEN = "L". MS0153-E-03 2005/06 - 16 - ASAHI KASEI [AK4571] 2.5 Bass Boost The AK4571 has an analog bass boost that is activated by mounting a resistor and a capacitor between LBFO-LBFI, and RBFO-RBFI respectively as Figure 6 shows. Bass frequencies can be amplified up to 20dB by selecting an appropriate resistor. Cut-off frequency shifts as the capacitor value varies. External Circuit Cb Rb LBFI/RBFI LBFO/RBFO Figure 6 Analog Bass Boost Circuit Bass Boost 25 Gain[dB] 20 Rb=360k Cb=1nF Rb=360k Cb=4.7nF 15 Rb=120k Cb=2.2nF 10 5 0 10 100 1000 10000 100000 Frequency[Hz] Figure 7 Bass Boost Characteristics MS0153-E-03 2005/06 - 17 - ASAHI KASEI [AK4571] 2.6 2.6.1 HID (Human Interface Device) HID Overview The AK4571 has two pins for incrementing or decrementing the lineout volume (INC pin and DEC pin), and has a pin for the control of mute (OMUTE pin). For example, the lineout volume slider in a Windows application automatically moves up at the rising edge of INC pin. This means that the value in the Windows program is synchronized with the device's hardware value. If a button is pressed, the internal bit assigned to it is set to "1". Based on the USB spec for HID, the host knows whether the INC button and/or DEC button and/or OMUTE buttons are pressed or not by periodically issuing an Interrupt transfer request. The AK4571 notifies the host of the status change, but does not change the value itself. The application program changes the value by issuing a SET FEATURE REQUEST. 2.6.2 HID Details The AK4571 has Interface (#3) and Interrupt Endpoint (#4: 1 byte) commands for HID. Figure 8 shows hierarchy of HID Interface. Interface #3 Standard Interface Descriptor Interface Number Interface Class(HID) etc. Descriptor Type Length of Report Descriptor etc. HID Descriptor EP address Interrupt Endpoint etc. Endpoint Descriptor Figure 8 Hierarchy of HID Interface Interrupt Endpoint is 1 byte, and lower 3 bits are valid. Bit 7 Bit 6 Bit 5 "0" "0" "0" Bit 4 "0" Bit 3 "0" Bit 2 OMUTE Bit 1 DEC Bit 0 INC Internal bits[2:0] are set to "1" at the rising edge of OMUTE, INC or DEC pins, and are cleared to "0" at the falling edge of these respective pins. The AK4571 transmits 1 byte of data through the Interrupt Pipe. If none of the buttons are pressed or if a button is continually pressed, the AK4571 sends NAK to the host. MS0153-E-03 2005/06 - 18 - ASAHI KASEI [AK4571] bInterval SOF Interrupt Transfer "1" NAK NAK NAK "0" NAK OMUTE DEC INC Figure 9 Interrupt Transfer Timing illustrates a switch de-bounce circuit (highly recommended) 3.3V IMUTE OMUTE DEC INC 0.1u 47K Figure 10 Switch De-Bounce Circuit Figure 10 illustrates a switch de-bounce circuit (highly recommended) If HID function is not used, please connect OMUTE pin, DEC pin, INC pin, to DGND. 2.6.3 IMUTE pin and MSTAT pin The AK4571 has an IMUTE pin for mute control of the recording path. Mute status toggles on the rising edge of the IMUTE pin. Note that pressing a physical button connected to IMUTE changes the internal state. This may cause an inconsistent mute state between the device and the Windows application. MSTAT pin reflects the actual mute status of the device. This limitation comes from the fact that the Windows OS does not support HID audio for recording. The MSTAT pin is forced to "L" in suspend mode regardless of previous state. MSTAT = (Internal IMUTE status) & SUS_N; Normal Operation: "H" -> Mute ON "L" -> Mute OFF Suspend State: "L" Figure 10 illustrates a switch de-bounce circuit (highly recommended) If IMUTE pin is not used, please connect it to DGND. MS0153-E-03 2005/06 - 19 - ASAHI KASEI [AK4571] 2.7 Audio Format The AK4571 supports only the 16-bit, 2's compliment audio format, and outputs LSB first. 1) 16bit mono data format on the USB (A/D data) Sample # bit position #1 mono Lower Upper 8 bit 8 bit 0-7 8-15 #2 mono Lower Upper 8bit 8 bit 0-7 8-15 #3 mono Lower Upper 8 bit 8 bit 8-15 8-15 ... ... ... ... 2) 16bit stereo data format on the USB (D/A data) Sample # bit position #1 Left channel data Lower Upper 8 bit 8 bit 0-7 8-15 Right channel data Lower Upper 8 bit 8 bit 0-7 8-15 Left channel data Lower Upper 8 bit 8 bit 0-7 8-15 MS0153-E-03 #2 Right channel data Lower Upper 8bit 8 bit 0-7 8-15 ... ... ... ... 2005/06 - 20 - ASAHI KASEI [AK4571] 2.8 Device topology and function USB audio devices must report their capabilities to the host and must report the topology that describes the connections between blocks. Figure 11 shows the topology of the AK4571. The host obtains the capabilities and connection diagram from the device by reading the Audio Control (AC) Interface Descriptor. The volume, mute, and sampling rate are controlled via Audio Class Specific Requests. 1) IN Endpoint#1 for A/D data is related to the MIC signal that is described as [OT1]. The MIC signal is amplified via FU1 and is digitized by the A/D converter and transmitted to the host. 2) OUT Endpoint#2 for D/A data is related to the Lineout. The D/A analog signal is mixed with the MIC analog signal that is amplified through FU2. The mixed analog signal can be attenuated/boosted by FU3, and is output via Lineout. 3) Endpoint#3 for HID is related to playback mute and volume up/down. OUTPUT INPUT Audio Streaming Interface #1 IN Endpoint #1 Audio Control Interface #0 Microphone MIC (+20dB) IPGA SU1 IT1 FU1 ID:5 ID:1 A/D OT1 ID:2 ID:7 FU2 ID:6 OPGA MU1 D/A (Analog) IT2 ID:3 Audio Streaming Interface #2 OUT Endpoint #2 D/A FU3 ID:8 ID:9 LineOut OT2 ID:4 HID Interface #3 IN Endpoint #3 Figure 11 AK4571 Topology MS0153-E-03 2005/06 - 21 - ASAHI KASEI [AK4571] 2.8.1 Terminal/Units a) Input Terminal (IT) IT is abbreviation of Input Terminal: IT1 (Microphone Input ID:1), IT2 (D/A Input ID:3) b) Output Terminal (OT) OT is abbreviation of Output Terminal: OT1(A/D Output ID:2), OT2 (Lineout ID:4) c) FU (Feature Unit) The FU (Feature Unit) describes that the AK4571 has volume/mute/bass-boost functions by setting the bmaControls(0), bmaControls(1) , bmaControls(2) to "1". The bit position assigned to the bass-boost function is D8, the length of bcontrolSize for FU3 is 0x02, and others are 0x01. bmaControl(0) means master channel. The AK4571 controls DAC mute or bass-boost via the master channel, and controls DAC volume via channel 1 and channel 2 controls. Since the AK4571 input is a single-channel, it controls both ADC mute and volume via the master channel. e) MU (Mixer Unit) The MU (Mixer Unit) describes mixing and volume control functions. Each input channel is connected to all output channels per the USB Audio Class specification shown in Figure 12. Only mixing function is available in the AK4571 because the volume is controlled via Feature Unit. Therefore, bitmap of bmControl in Mixer Unit Descriptor is all "0". Mixer Unit 1 Master Channel (Microphone) Lch Lineout D/A Lch Rch Lineout D/A Rch Figure 12 Channel Connection f) SU (Selector Unit) Selector Unit is unnecessary for the AK4571's topology. Windows application does not display playback MIC volume slider if the AK4571 does not define Selector Unit. MS0153-E-03 2005/06 - 22 - ASAHI KASEI [AK4571] 2.8.2 Descriptor Overview When the AK4571 is connected to the USB bus, the host assigns unique address to the device first, and starts reading of the device's information via a default pipe. Descriptors consist of (1) Device Descriptor, (2) Configuration Descriptor, (3) Interface Descriptor, (4) Endpoint Descriptor. The AK4571 is defined as a device with one configuration and four interfaces. It has one Endpoint (EP) for Interface#0, one EP for Interface#1 (ADC), one for Interface#2 (DAC), and one for Interface#3 (HID) Device Device Descriptor Configuration Configuration Descriptor Interface Interface 0 Interface 1 Interface 2 Interface 3 Standard Audio Control Interface Descriptor Standard AS Interface Descriptor Alt. Setting 0 Standard AS Interface Descriptor Alt. Setting 0 Standard AS Interface Descriptor Alt. Setting 0 Class-Specific Audio Control Interface Descriptor Standard AS Interface Descriptor Alt. Setting 1 Standard AS Interface Descriptor Alt. Setting 1,2 HID Descriptor Input Terminal Descriptor Class-Specific Audio Streaming Interface Descriptor Class-Specific Audio Streaming Interface Descriptor Output Terminal Descriptor Class-Specific AS Format Type Descriptor Class-Specific AS Format Type Descriptor Feature Unit Descriptor(Mute,Volume,AGC) Mixer Unit Descriptor Selector Unit Descriptor Standard AS Isochronous Endpoint Descriptor Standard AS Isochronous Endpoint Descriptor Class-Specific AS Isochronous Endpoint Descriptor Class-Specific AS Isochronous Endpoint Descriptor IN Endpoint (Isochronous) Standard HID Interrupt Endpoint Descriptor IN Endpoint (interrupt) OUT Endpoint (Isochronous) Figure 13 Descriptor Hierarchy MS0153-E-03 2005/06 - 23 - ASAHI KASEI [AK4571] Device Descriptor Device Descriptor includes product name, manufacturer name, product revision, etc. And it also includes the number of configurations (The AK4571 is a one configuration device). Configuration Descriptor Configuration Descriptor includes the device type, which is described as bus-powered device or self-powered device, power consumption, number of interfaces, etc. The AK4571 is defined as a low-power bus-powered device with four interfaces. Interface Descriptor The AK4571 has four interfaces as follows. a) Audio Control (AC) Interface b) Audio Streaming (AS) Interface1 for A/D converter c) Audio Streaming (AS) Interface2 for D/A converter d) HID Interface for Mute & Volume Control AC Interface includes topology information, Input/Output Terminal information, and Function information in addition to the standard Class Interface Descriptor. AS Interface also includes audio format and sampling frequencies. The AK4571 has two alternates for Interface#1 (ADC), and Interface#2 (DAC). The default state is Alt0, and Alt 0 does not occupy USB bandwidth. Alt 1 is used as the interface for audio streaming data. The bandwidth occupied by A/D data and D/A data are 100 bytes and 200 bytes respectively, and each value is described in the wMaxPacketSize field in the Standard Endpoint Descriptor in each interface. Endpoint Descriptor Endpoint 0 (EP0: default pipe) is used for AC Interface. The EP for the AS interface includes IN/OUT, synchronization type, maximum packet length, etc. The AK4571 also has one Interrupt Endpoint for the HID Interface. The AK4571 returns one byte of information at the Interrupt transfer just after the playback volume or mute buttons are pressed. If no buttons are pressed, the AK4571 returns NAK. MS0153-E-03 2005/06 - 24 - ASAHI KASEI [AK4571] 3 Descriptors in Detail 3.1 Device Descriptor Offset 0 1 2 4 5 6 7 8 10 Field bLength bDescriptorType BcdUSB bDeviceClass bDeviceSubClass bDeviceProtocol bMaxPacketSize0 IdVendor IdProduct 12 14 15 16 17 bcdDevice IManufacturer Iproduct ISerialNumber bNumConfigurations 3.2 Configuration Descriptor Size 1 1 2 1 1 1 1 2 2 Value 0x12 0x01 0x0110 0x00 0x00 0x00 0x08 0x0556 0x0004 2 1 1 1 1 0x0100 0x01 0x02 0x00 0x01 Description Size of this descriptor in bytes DEVICE descriptor 1.10 - current revision of USB spec. Device defined at Interface level Unused Unused 8 bytes AKM's Vendor ID Upper 00 means Audio Product Lower 03 means AKM product ID Device release code " AKM " " AK4571" Unused One configuration Table Device Descriptor Offset 0 1 2 4 5 6 7 8 Field Blength bDescriptorType WTotalLength BnumInterfaces bConfigurationValue IConfiguration BmAttributes MaxPower Size 1 1 2 1 1 1 1 1 Value 0x09 0x02 0x011C 0x04 0x01 0x00 0x80 0x31 Description Size of this descriptor CONFIGURATION descriptor length of entire configuration block total 284 bytes including this interface descriptor. Four interfaces index of this configuration null string supports Bus Powered Device 98mA MS0153-E-03 2005/06 - 25 - ASAHI KASEI [AK4571] 3.3 Interface Descriptor # 0 3.3.1 Standard Audio Control Interface Descriptor Offset 0 1 2 3 4 5 6 7 8 3.3.2 Offset 0 1 2 3 5 Field bLength bDescriptorType bInterfaceNumber bAlternateSetting bNumEndpoints bInterfaceClass bInterfaceSubclass bInterfaceProtocol IInterface Size 1 1 1 1 1 1 1 1 1 Value 0x09 0x04 0x00 0x00 0x00 0x01 0x01 0x00 0x00 Description Size of this descriptor INTERFACE descriptor Index of this interface Index of this setting only uses Endpoint 0 AUDIO AUDIO_CONTROL not vendor or class specific null string Table Standard Interface Descriptor Class-Specific Audio Control Interface Descriptor Field BLength bDescriptorType bDescriptorSubtype BcdADC wTotalLength Size 1 1 1 2 2 Value 0x0A 0x24 0x01 0x0100 0x0065 7 8 binCollection baInterfaceNr(0) 1 1 0x02 0x01 9 baInterfaceNr(1) 1 0x02 Description Size of this descriptor CS_INTERFACE HEADER subtype Revision of class specification - 1.00 Total size of class-specific Audio Control Interface descriptors 101 bytes (includes this descriptor) The number of streaming interfaces Streaming interface number 1 belongs to this audio control interface. IN Interface Streaming interface number 2 belongs to this audio control interface. OUT Interface MS0153-E-03 2005/06 - 26 - ASAHI KASEI [AK4571] 3.3.3 Terminal Descriptor(ID=3) D/A Input Terminal Offset Field 0 Blength 1 BDescriptorType 2 bDescriptorSubtype 3 BterminalID 4 WterminalType 6 BassocTerminal 7 BnrChannels 8 WChannelConfig 10 IchannelNames 11 Iterminal 3.3.4 Size 1 1 1 1 2 1 1 2 1 1 Value 0x0C 0x24 0x02 0x03 0x0101 0x04 0x02 0x0003 0x00 0x00 Description Size of this descriptor CS_INTERFACE INPUT_TERMINAL subtype ID of this terminal Terminal is USB streaming OUT Associated with Output Terminal is 0x04 Two channel Left/Right Front Unused Unused Value 0x09 0x24 0x03 0x04 0x0301 0x03 0x08 0x00 Description Size of this descriptor CS_INTERFACE OUTPUT_TERMINAL subtype ID of this terminal Terminal is Speaker Associate with Input Terminal 0x03 From Feature Unit (ID8) Unused Terminal Descriptor(ID=4) Lineout Terminal Offset Field 0 Blength 1 BdescriptorType 2 bdescriptorSubtype 3 BterminalID 4 WterminalType 6 BassocTerminal 7 BsourceID 8 Iterminal Size 1 1 1 1 2 1 1 1 MS0153-E-03 2005/06 - 27 - ASAHI KASEI [AK4571] 3.3.5 Terminal Descriptor(ID=1) Analog Microphone Input Terminal Offset Field Size 0 Blength 1 1 bDescriptorType 1 2 bDescriptorSubtype 1 3 BterminalID 1 4 WTerminalType 2 6 BAssocTerminal 1 7 BNrChannels 1 8 WChannelConfig 2 10 IChannelNames 1 11 Iterminal 1 3.3.6 Value 0x0C 0x24 0x02 0x01 0x0201 0x02 0x01 0x0000 0x00 0x00 Description Size of this descriptor CS_INTERFACE INPUT_TERMINAL subtype ID of this terminal Terminal is Microphone Associated with Output Terminal 0x02 One channel Mono sets no position bit Unused Unused Value 0x09 0x24 0x03 0x02 0x0101 0x01 0x05 0x00 Description Size of this descriptor CS_INTERFACE OUTPUT_TERMINAL subtype ID of this terminal Terminal is USB streaming Associate with Input Terminal is 0x01 From Feature Unit (ID5) Unused Terminal Descriptor (ID=2) A/D Output Terminal Offset Field 0 Blength 1 BdescriptorType 2 bdescriptorSubtype 3 BterminalID 4 WterminalType 6 BassocTerminal 7 BsourceID 8 Iterminal Size 1 1 1 1 2 1 1 1 MS0153-E-03 2005/06 - 28 - ASAHI KASEI [AK4571] 3.3.7 Feature Unit Desciptor(ID=5) Microphone Recording Volume Unit Offset Field Size 0 Blength 1 1 BdescriptorType 1 2 BdescriptorSubtype 1 3 BunitID 1 4 BsourceID 1 5 BcontrolSize 1 6 bmaControls(0) 1 7 Ifeature 1 3.3.8 Value 0x08 0x24 0x06 0x06 0x01 0x01 0x03 0x00 Description Size of this descriptor CS_INTERFACE FEATURE_UNIT descriptor subtype ID of this feature Unit From Input Terminal (Microphone) One byte Control Array D0(Mute) D1(Volume) supported Unused Value 0x0D 0x24 0x06 0x08 0x09 0x02 0x0101 Description Size of this descriptor CS_INTERFACE FEATURE_UNIT descriptor subtype ID of this feature Unit From Mixer Unit(ID9) Two byte Control Array D0(Mute) , D8(Bass Boost)is enable for channel0 D1(Volume) control is enable for channel 1 D1(Volume) control is enable for channel 2 Unused Feature Unit Desciptor(ID=8) Lineout Volume/Bass Boost Unit Offset Field Size 0 blength 1 1 bdescriptorType 1 2 bdescriptorSubtype 1 3 bunitID 1 4 BsourceID 1 5 BcontrolSize 1 6 bmaControls(0) 1 8 10 12 Description Size of this descriptor CS_INTERFACE FEATURE_UNIT descriptor subtype ID of this feature Unit From Selector Unit One byte Control Array D0(Mute), D1(Volume) supported Unused Feature Unit Desciptor(ID=6) Microphone Playback Volume Unit Offset Field Size 0 Blength 1 1 BdescriptorType 1 2 BdescriptorSubtype 1 3 BunitID 1 4 BsourceID 1 5 BcontrolSize 1 6 bmaControls(0) 1 7 Ifeature 1 3.3.9 Value 0x08 0x24 0x06 0x05 0x07 0x01 0x03 0x00 bmaControls(1) bmaControls(2) IFeature 1 1 1 0x0002 0x0002 0x00 MS0153-E-03 2005/06 - 29 - ASAHI KASEI [AK4571] 3.3.10 Mixer Unit Desciptor(ID=9) Mixer Unit (D/A and Microphone) Offset 0 1 2 3 4 5 6 7 Field blength bdescriptorType bdescriptorSubtype bunitID bnrInPins baSourceID(1) baSourceID(2) bnrChannels Size 1 1 1 1 1 1 1 1 Value 0x0D 0x24 0x04 0x09 0x02 0x06 0x03 0x02 Description Size of this descriptor CS_INTERFACE MIXER_UNIT subtype ID of this terminal Number of Input Pin From Feature Unit 2(ID6) From IT(ID3) 8 10 11 wChannnelConfig iChannelNames bmControl 2 1 1 0x0003 0x00 0x00 12 Imixer 1 0x00 Index of String descriptor Value 0x07 0x24 0x05 0x07 0x01 0x01 0x00 Description Size of this descriptor CS_INTERFACE Selector_UNIT descriptor subtype ID of this feature Unit Inputs Pins From Input Terminal Unused Number of logical output channels in the Mixer's output audio channel cluster describes the spatial location L/R front Index of String descriptor bit map no control 3.3.11 Selector Unit Desciptor(ID=7) Offset 0 1 2 3 4 5 6 Field blength bdescriptorType bdescriptorSubtype bunitID bNrInPins bSourceID(1) IFeature Size 1 1 1 1 1 1 1 MS0153-E-03 2005/06 - 30 - ASAHI KASEI [AK4571] 3.4 Interface Descriptor #1 3.4.1 Standard Interface descriptor <Alternate Setting 0> (A/D Audio Streaming Data) Zero Bandwidth Offset 0 1 2 3 4 5 6 7 8 Field bLength bDescriptorType bInterfaceNumber bAlternateSetting bNumEndpoints bInterfaceClass bInterfaceSubclass bInterfaceProtocol iInterface Size 1 1 1 1 1 1 1 1 1 Value 0x09 0x04 0x01 0x00 0x00 0x01 0x02 0x00 0x00 Description Length of this descriptor INTERFACE descriptor Index of this interface Index of this setting 0 Endpoint AUDIO AUDIO_STREAMING Unused null string MS0153-E-03 2005/06 - 31 - ASAHI KASEI [AK4571] 3.4.2 Offset 0 1 2 3 4 5 6 7 8 3.4.3 Offset 0 1 2 3 4 5 3.4.4 Offset 0 1 2 3 4 5 6 7 8 11 14 17 20 23 26 Standard Interface descriptor <Alternate Setting 1> (A/D Audio Streaming Data) Field bLength bDescriptorType bInterfaceNumber bAlternateSetting bNumEndpoints bInterfaceClass bInterfaceSubclass bInterfaceProtocol iInterface Size 1 1 1 1 1 1 1 1 1 Value 0x09 0x04 0x01 0x01 0x01 0x01 0x02 0x00 0x00 Description Length of this descriptor INTERFACE descriptor Index of this interface Index of this setting 1 Endpoint AUDIO AUDIO_STREAMING Unused null string Class-specific audio streaming interface descriptor <Alt 1> Field bLength bDescriptorType bDescriptorSubtype bTerminalLink bDelay wFormatTag Size 1 1 1 1 1 2 Value 0x07 0x24 0x01 0x02 0x00 0x0001 Description Length of this descriptor CS_INTERFACE descriptor AS_GENERAL Unit ID of terminal(Output Terminal ID) Interface delay PCM Value 0x1D 0x24 0x02 0x01 0x01 0x02 0x10 0x07 0x001F40 0x002B11 0x003E80 0x005622 0x007D00 0x00AC44 0x00BB80 Description Size of this descriptor CS_INTERFACE FORMAT_TYPE FORMAT_TYPE_I One channel Two bytes per slot 16 bits Seven frequencies 8000Hz 11025Hz 16000Hz 22050Hz 32000Hz 44100Hz 4800Hz Type I format type descriptor Field blength bDescriptorType bdescriptorSubtype bformatType bNrChannels bSubFrameSize bBitResolution bSamFreqType tSamFreq[0] tSamFreq[1] tSamFreq[2] tSamFreq[3] tSamFreq[4] tSamFreq[5] tSamFreq[6] Size 1 1 1 1 1 1 1 1 3 3 3 3 3 3 3 MS0153-E-03 2005/06 - 32 - ASAHI KASEI [AK4571] 3.4.5 Offset 0 1 2 3 4 6 7 8 3.4.6 Offset 0 1 2 3 4 5 Standard Endpoint descriptor Field bLength bDescriptorType bendpointAddress bmAttributes wMaxPacketSize bInterval bRefresh bSynchAddress Size 1 1 1 1 2 1 1 1 Value 0x09 0x05 0x81 0x05 0x0064 0x01 0x00 0x00 Description Length of this descriptor ENDPOINT descriptor Endpoint 1, IN direction Isochronous, asynchronous 2byte*50sample*1ch=100 byte/frame One packet every frame (Must be set to 1) Unused Unused Class-specific isochronous audio data endpoint descriptor Field bLength bDescriptorType bDescriptorSubtype bmAttributes bLockDelayUnits wLockDelay Size 1 1 1 1 1 2 Value 0x07 0x25 0x01 0x01 0x00 0x0000 Description Size of this descriptor CS_ENDPOINT EP GENERAL sample rate control Unused MS0153-E-03 2005/06 - 33 - ASAHI KASEI [AK4571] 3.5 Interface Descriptor #2 3.5.1 Standard Audio Streaming Interface descriptor <Alternate Setting 0> (D/A Audio Streaming Data) Zero Bandwidth Offset 0 1 2 3 4 5 6 7 10 3.5.2 Offset 0 1 2 3 4 5 6 7 8 3.5.3 Offset 0 1 2 3 4 5 Field bLength bDescriptorType bInterfaceNumber bAlternateSetting bNumEndpoints bInterfaceClass bInterfaceSubclass bInterfaceProtocol iInterface Size 1 1 1 1 1 1 1 1 1 Value 0x09 0x04 0x02 0x00 0x00 0x01 0x02 0x00 0x00 Description Length of this descriptor INTERFACE descriptor Index of this interface Index of this setting endpoints 0 AUDIO AUDIO_STREAMING Unused null string Operational Interface descriptor <Alternate Setting 1> (D/A Audio Streaming Data) Field BLength bDescriptorType bInterfaceNumber bAlternateSetting bNumEndpoints bInterfaceClass bInterfaceSubclass bInterfaceProtocol iInterface Size 1 1 1 1 1 1 1 1 1 Value 0x09 0x04 0x02 0x01 0x01 0x01 0x02 0x00 0x00 Description Length of this descriptor INTERFACE descriptor Index of this interface Index of this setting Streaming Endpoint AUDIO AUDIO_STREAMING Unused null string Class-specific audio streaming interface descriptor<Alternate Setting 1> Field bLength bDescriptorType bDescriptorSubtype bTerminalLink bDelay wFormatTag Size 1 1 1 1 1 2 Value 0x07 0x24 0x01 0x03 0x00 0x0001 Description Length of this descriptor CS_INTERFACE descriptor AS_GENERAL Unit ID of Terminal(Input Terminal) Interface delay PCM MS0153-E-03 2005/06 - 34 - ASAHI KASEI [AK4571] 3.5.4 Offset 0 1 2 3 4 5 6 7 8 11 14 17 20 23 26 Type I format type descriptor<Alternate Setting 1> Field blength bDescriptorType bDescriptorSubtype bFormatType bNrChannels bSubFrameSize bBitResolution bSamFreqType tSamFreq[0] tSamFreq[1] tSamFreq[2] tSamFreq[3] tSamFreq[4] tSamFreq[5] tSamFreq[6] 3.5.5 Endpoint descriptor Offset 0 1 2 3 4 6 7 8 Field bLength bDescriptorType bEndpointAddress bmAttributes wMaxPacketSize bInterval bRefresh bSynchAddress 3.5.6 Offset 0 1 2 3 4 5 Size 1 1 1 1 1 1 1 1 3 3 3 3 3 3 3 Size 1 1 1 1 2 1 1 1 Value 0x1D 0x24 0x02 0x01 0x02 0x02 0x10 0x07 0x001F40 0x002B11 0x003E80 0x005622 0x007D00 0x00AC44 0x00BB80 Value 0x09 0x05 0x02 0x09 0x00C8 0x01 0x00 0x00 Description Size of this descriptor CS_INTERFACE FORMAT_TYPE FORMAT_TYPE_I Two channels Two bytes per slot 16 bits Six frequencies 8000Hz 11025Hz 16000Hz 22050Hz 32000Hz 44100Hz 48000Hz Description Length of this descriptor ENDPOINT descriptor Endpoint 2, OUT direction Adaptive Isochronous 2byte*(48+2)sample*2ch=200 byte/frame 1millisecond (Must be set to 1) Unused Unused Class-specific isochronous audio data endpoint descriptor Field bLength bDescriptorType bDescriptorSubtype bmAttributes bLockDelayUnits wLockDelay Size 1 1 1 1 1 2 Value 0x07 0x25 0x01 0x01 0x00 0x0000 Description Size of this descriptor CS_ENDPOINT EP_GENERAL Sample rate control Unused Unused MS0153-E-03 2005/06 - 35 - ASAHI KASEI [AK4571] 3.6 Interface #3 (HID Class) 3.6.1 Standard Interface Descriptor Offset 0 1 2 3 4 5 6 7 8 3.6.2 Offset 0 1 2 4 5 6 7 3.6.3 Offset 0 1 2 3 4 6 Field bLength bDescriptorType bInterfaceNumber bAlternateSetting bNumEndpoints bInterfaceClass bInterfaceSubclass bInterfaceProtocol iInterface Size 1 1 1 1 1 1 1 1 1 Value 0x09 0x04 0x03 0x00 0x01 0x03 0x00 0x00 0x00 Description Size of this descriptor INTERFACE descriptor Index of this interface Index of this setting endpoint 1 HID Non-Boot Device Unused null string Size 1 1 2 1 1 1 2 Value 0x09 0x21 0x0110 0x00 0x01 0x22 0x001f Description Size of this descriptor HID HID spec rev #1.10 HID Descriptor Field bLength bDescriptorType bcdHID bCoundtryCode bNumDescriptor bDescriptorType bDescriptorLength Report Descriptor 31 bytes Endpoint Descriptor Field bLength bDescriptorType bendpointAddress bmAttributes wMaxPacketSize wInterval Size 1 1 1 1 2 1 Value 0x07 0x05 0x83 0x03 0x0001 0x40 Description Length of this descriptor ENDPOINT descriptor Endpoint 3, IN direction Interrupt 64ms Interval MS0153-E-03 2005/06 - 36 - ASAHI KASEI [AK4571] String descriptor String descriptors use UNICODE. 3.6.4 Language ID (0x00) Index Offset Field Size 0 bLength 1 1 bDescriptorType 1 2 bString 2 3.6.5 Offset 0 1 2 Value 0x04 0x03 0x0409 Description Length of this descriptor STRING descriptor "English(US)" iManufacterer(0x01) Field in Device Descriptor for AKM Field Size Value Description bLength 1 0x34 Length of this descriptor bdescriptorType 1 0x03 STRING descriptor bString 50 0x0041 "AKM " 0x004B 0x004D 0x0020 0x0020 0x0020 0x0020 0x0020 0x0020 0x0020 0x0020 0x0020 0x0020 0x0020 0x0020 0x0020 0x0020 0x0020 0x0020 0x0020 0x0020 0x0020 0x0020 0x0020 0x0020 MS0153-E-03 2005/06 - 37 - ASAHI KASEI [AK4571] 3.6.6 Offset 0 1 2 iProduct (0x02) Field in Device Descriptor Field Size Value bLength 1 0x34 bDescriptorType 1 0x03 bString 50 0x0041 0x004B 0x0034 0x0035 0x0037 0x0031 0x0020 0x0020 0x0020 0x0020 0x0020 0x0020 0x0020 0x0020 0x0020 0x0020 0x0020 0x0020 0x0020 0x0020 0x0020 0x0020 0x0020 0x0020 0x0020 Description Length of this descriptor STRING descriptor "AK4571 " MS0153-E-03 2005/06 - 38 - ASAHI KASEI [AK4571] 4 Standard Device Requests 4.1 Clear Feature The AK4571 return ACK without ERROR Offset Field Size Value 0 bmRequestType 1 0x00 0x02 1 bRequest 1 0x01 2 wValue 2 0x0000 0x0001 4 wIndex 2 0x0000 6 wLength 2 0x000 4.2 Get Configuration The AK4571 returns "1". Offset Field 0 bmRequestType 1 bRequest 2 wValue 4 wIndex 6 wLength Size 1 1 2 2 2 Value 0x80 0x08 0x0000 0x0000 0x0001 Description Device Endpoint CLEAR_FEATURE clear ENDPONT0 HALT clear REMOTE_WAKEUP Description GET_CONFIGURATION 4.3 Get Descriptor The AK4571 returns the descriptor that is specified in wValue field. Offset Field Size Value Description 0 bmRequestType 1 0x80 1 bRequest 1 0x06 GET_DESCRIPTOR 2 wValue 2 0xZZZZ ZZZZ is assigned by host: High Byte is Desc. type, Low Byte is Index. DEVICE : 0x0100 : (Index is 0 only) CONFIGURATION : 0x0200 4 wIndex 2 0x0000 6 wLength 2 0xZZZZ Descriptor Length (ZZZZ is assigned by host) 4.4 Get Interface The AK4571 returns the current alternate value for the interface that is specified in wIndex field. "0x00" or "0x01" is returned for Interface#1, or Interface#2. Only "0x00" is returned for Interface#0 or Interface3. Offset Field Size Value Description 0 bmRequestType 1 0x81 1 bRequest 1 0x0A GET_INTERFACE 2 wValue 2 0x0000 ZERO Audio Control Interface 4 wIndex 2 0x0000 Audio Streaming Interface for A/D 0x0001 Audio Streaming Interface for D/A 0x0002 HID Interface 0x0003 6 wLength 2 0x0001 AK4571 has both a zero bandwidth Audio Streaming Interface and a normal Audio Streaming Interface. MS0153-E-03 2005/06 - 39 - ASAHI KASEI [AK4571] 4.5 Get Status 4.5.1 Get Status Offset 0 Field bmRequestType Size 1 Value Description 0x80 DEVICE 0x81 INTERFACE 0x82 ENDPOINT 1 bRequest 1 0x00 GET_STATUS 2 wValue 2 0x0000 ZERO bmRequestType is "DEVICE" 4 wIndex 2 0x0000 bmRequestType is "INTERFACE " 0x0001 bmRequestType is I"NTERFACE" 0x0002 bmRequestType is "INTERFACE " 0x0003 bmRequestType is "ENDPOINT" 0x0000 bmRequestType is "ENDPOINT" *) 0x0081 bmRequestType is "ENDPOINT" *) 0x0002 bmRequestType is "ENDPOINT" *) 0x0083 0x0084 6 wLength 2 0x0002 *)This request is valid after "SET_INTERFACE request (except for Alt0)" for each interface is issued. If the AK4571 receives GET_STATUS request prior to SET_INTERFACE request, it returns STALL. If SET_INTERFACE request with Alt1 is issued, GET_STATUS request is valid even if alternate value is returned to "0". The AK4571 has the following two bytes. a) Device: 0x0000 (Bus Powered, No-remote wakeup) b) Interface: 0x0000 c) Endpoint: 0x0000 4.6 Set Address The AK4571 stores wValue, and returns ACK. It responds to the requests in which this address is specified after receiving this request. Offset Field Size Value Description 0 BmRequestType 1 0x00 Zero 1 BRequest 1 0x05 SET_ADDRESS 2 wValue 2 0xZZZZ Device Address : ZZZZ is assigned by host 4 wIndex 2 0x0000 Zero 6 wLength 2 0x0000 Zero 4.7 Set Configuration The AK4571 is set to the configuration state, and returns ACK. As the AK4571 is defined as a single-configuration device, only "0x00" or "0x01" are valid terms. Offset Field Size Value Description 0 bmRequestType 1 0x00 Zero 1 bRequest 1 0x09 SET_CONFIGURATION 2 wValue 2 0x0000 Unconfigured State 0x0001 AK4571 is set to configuration state others Unconfigured State 4 wIndex 2 0x0000 Zero 6 wLength 2 0x0000 Zero MS0153-E-03 2005/06 - 40 - ASAHI KASEI [AK4571] 4.8 Offset 0 Set Feature Field bmRequestType Size 1 Value Description 0x00 Device 0x02 Endpoint 1 bRequest 1 0x03 SET_FEATURE 2 wValue 2 0x0000 ENDPOINT(0) HALT 0x0001 REMOTRE_WAKEUP 4 wIndex 2 0x0000 6 wLength 2 0x000 If wValue is ENDPOINT(0) HALT, the AK4571 returns STALL. If wValue is REMOTE_WAKEUP, the AK4571 returns ACK without additional processing because it does not have a remote wakeup function. 4.9 Set Interface The AK4571 set alternate value that is specified in wValue for the interface that is specified in wIndex field. Either Alt0 or Alt1 can be set for Iterface#1 or Interface #2. Only Alt0 is valid for Interface#0 or Interface#3. Offset Field Size Value Description 0 bmRequestType 1 0x01 ONE D7 0 = Host to device D6..5 0 = Standard request D4..0 1 = Recipient is interface 1 bRequest 1 0x0B SET_INTERFACE 2 wValue 2 0x0000 or Zero bandwidth Alternate Setting 0x0001 Normal Isochronous Streaming 4 wIndex 2 0x0000 Audio Control Interface 0x0001 Audio Streaming Interface IN 0x0002 Audio Streaming Interface OUT 0x0003 HID Interface 6 wLength 2 0x0000 Zero 4.10 Synch Frame The AK4571 does not support this request. MS0153-E-03 2005/06 - 41 - ASAHI KASEI [AK4571] 5 Device Specific Requests If the AK4571 receives a request that is not supported, or if it receives an invalid parameter, the AK4571 returns STALL. 5.1 Set Feature Unit Control Request 5.1.1 Mute Control Mute is controlled via the master channel. Offset Field Size 0 bmRequestType 1 1 bRequest 1 2 wValue 2 4 wIndex 2 6 wLength Parameter: Offset Field 0 bMute 2 Size 1 Both left channel and right channel of lineout are muted at the same time. Value Description 0x21 0x01 SET_CUR 0x0100 MUTE_CONTROL | CHANNEL_0 0x0500 Mute for MIC Recording Volume | interface 0 0x0600 Mute for MIC Playback Volume | interface 0 0x0800 Mute for LineOut Volume | interface 0 0x0001 The Length of Mute Control Parameter Block Value 0x01 0x00 Description TRUE FALSE If invalid data is set, (i.e the parameter is not one of the above values), the AK4571 returns STALL at data phase, and keeps previous value. 5.1.2 Bass Boost Offset Field 0 bmRequestType 1 bRequest 2 wValue 4 wIndex 6 wLength Parameter: Offset Field 0 bBassBoost Size 1 1 2 2 2 Value 0x21 0x01 0x0900 0x0800 0x0001 Description SET_CUR BASS_BOOST | CHANNEL_0 LineOut BASS BOOST | interface 0 The Length of Mute Control Parameter Block Size 1 Value 0x01 0x00 Description TRUE FALSE If invalid data is set, (i.e the parameter is not one of the above values), the AK4571 returns STALL at data phase, and keeps previous value. MS0153-E-03 2005/06 - 42 - ASAHI KASEI [AK4571] 5.1.3 Volume Control The ADC volume is controlled via the master channel, and the DAC volume is controlled via channel 1 (Left channel) and channel 2 (Right channel) independently. Offset 0 1 2 Field bmRequestType bRequest wValue Size 1 1 2 4 wIndex 2 6 wLength 2 Value 0x21 0x01 0x0200 0x0201 0x0202 0x0500 0x0600 0x0800 0x0800 0x0002 Description SET_CUR A/D: VOLUME_CONTROL | Master Channel DAC: VOLUME_CONTROL | CHANNEL_1 DAC: VOLUME_CONTROL | CHANNEL_2 A/D Feature Unit ID: 0x05 (MIC REC Master CH) A/D Feature Unit ID: 0x06 (MIC PLAY Master CH) D/A Feature Unit ID: 0x08 (Lineout Lch Volume) D/A Feature Unit ID: 0x08 (Lineout Rch Volume) Lower Byte: Audio Control Interface (0x00) Volume Control Parameter: Offset Field Size Value Description 0 wVolume 2 0xZZZZ The value is set by host The data format for volume follows USB's "Device Class Definition for Audio Devices". If the parameter value is larger than the maximum value, the AK4571 defaults to the maximum value. If the parameter is smaller than minimum value, it defaults to the minimum value. Volume for FU1 (ID5: MIC Recording), and FU2 (ID6: MIC Playback) The AK4571 recognizes the lower byte of the USB Audio Volume format as 00H. Volume Value USB Audio Class Format 24.0dB 0x7FFF --------------24.0dB 0x1800 23.0dB 0x17FF --------------0.0dB 0x0000 --------------30.0dB 0xE200 -31.0dB 0xE1FF -------31.0dB 0x8000 Volume for FU 3 (ID 8: LineOut) The AK4571 recognizes the lower byte of the USB Audio Volume format as 00H. Volume Value USB Audio Class Format 0.0dB 0x7FFF --------------0.0dB 0x0000 -1.0dB 0xFF00 -2.0dB 0xFE00 ---------------46.0dB 0xD200 -47.0dB 0xD100 ---------------47.0dB 0x8000 MS0153-E-03 2005/06 - 43 - ASAHI KASEI [AK4571] 5.2 Set Selector Unit Control Request 5.2.1 Selector Control Offset 0 1 2 4 6 Field bmRequestType bRequest wValue wIndex wLength Size 1 1 2 2 2 Value 0x21 0x01 0x0000 0x0700 0x0001 Parameter: Offset Field Size Value 0 bSelector 1 0xZZ The AK4571 returns ACK, but ignores this value. Description SET_CUR ZERO SELECTOR UNIT CONTROL | Interface 0 The Length of Mute Control Parameter Block Description The value is set by host MS0153-E-03 2005/06 - 44 - ASAHI KASEI [AK4571] 5.3 Get Feature Unit Control Request 5.3.1 Mute Control Offset Field Size 0 bmRequestType 1 1 bRequest 1 2 wValue 2 4 wIndex 2 6 wLength 2 The AK4571 returns current value. Offset Field Size 0 bMute 1 Default: 5.3.2 Mute OFF (0x00): Mute ON (0x01): Bass Boost Control Offset Field Size 0 bmRequestType 1 1 bRequest 1 2 wValue 2 4 wIndex 2 6 wLength 2 The AK4571 returns current value. Offset Field Size 0 bBassBoost 1 Default Value 0xA1 0x81 0x0100 0x0500 0x0600 0x0800 Description 0x0001 GET_CUR MUTE_CONTROL | CHANNEL_0 Mute for MIC Recording Volume | interface 0 Mute for MIC Playback Volume | interface 0 Mute for Lineout Volume | interface 0 Lower Byte : Audio Control Interface(0x00) The Length of Mute Control Parameter Block Value 0x01 0x00 Description TRUE FALSE FU1 (ID5), FU3 (ID8) FU2 (ID6) Value 0xA1 0x81 0x0900 0x0800 0x0001 Description GET_CUR BASS_BOOST | CHANNEL_0 Feature Unit | interface 0 The Length of Mute Control Parameter Block Value 0x01 0x00 Description TRUE FALSE BASS BOOST OFF(0x00): MS0153-E-03 2005/06 - 45 - ASAHI KASEI [AK4571] 5.3.3 Volume Control Offset 0 1 Field bmRequestType bRequest Size 1 1 2 wValue 2 4 wIndex 2 6 wLength 2 Value 0xA1 0x81 0x82 0x83 0x84 0x0200 0x0201 0x0202 0x0500 0x0600 0x0800 0x0002 Description GET_CUR GET_MIN GET_MAX GET_RES VOLUME_CONTROL | Master CH (FU5, FU6) VOLUME_CONTROL | CHANNEL_1 (FU8) VOLUME_CONTROL | CHANNEL_2 (FU8) MIC Recording Volume | interface 0 MIC Playback Volume | interface 0 Lineout Volume | interface 0 Lower Byte: Audio Control Interface(0x00) Volume Control The AK4571 returns the following wVolume (two bytes). When it receives a request with other combinations, it returns STALL. bRequest wValue wIndex wVolume (2 bytes) Desciptorn 0x81 0x0200 0x0500 0xZZZZ Returns current MIC volume of recording path. 0x81 0x0200 0x0600 0xZZZZ Returns current MIC volume of playback path. 0x81 0x0201 0x0800 0xZZZZ Returns current Left channel volume of Lineout 0x81 0x0202 0x0800 0xZZZZ Returns current Right channel volume of Lineout 0x82 0x0200 0x0500 0xE100 Returns minimum MIC recording volume (-31dB) 0x82 0x0200 0x0600 0xE100 Returns minimum MIC playback volume (-31dB) 0x82 0x0201 0x0800 0xD100 Returns minimum Lineout volume (-47dB) 0x82 0x0202 0x0800 0xD100 Returns minimum Lineout volume (-47dB) 0x83 0x0200 0x0500 0x1800 Returns maximum MIC recording volume (+24dB) 0x83 0x0200 0x0600 0x1800 Returns maximum MIC playback volume (+24dB) 0x83 0x0201 0x0800 0x0000 Returns maximum Line Out Volume (0dB) 0x83 0x0202 0x0800 0x0000 Returns maximum Line Out Volume (0dB) 0x84 0x0200 0x0500 0x0100 Returns resolution of MIC recording volume (1dB) 0x84 0x0200 0x0600 0x0100 Returns resolution of MIC playback volume (1dB) 0x84 0x0201 0x0800 0x0100 Returns resolution of LineOut Volume (1dB) 0x84 0x0202 0x0800 0x0100 Returns resolution of LineOut Volume (1dB) Default: 0dB(0x0000) MS0153-E-03 2005/06 - 46 - ASAHI KASEI [AK4571] 5.4 Get Selector Unit Control Request 5.4.1 Selector Control Offset 0 1 2 4 6 Field bmRequestType bRequest wValue wIndex wLength Parameter: Offset Field 0 bSelector Size 1 1 2 2 2 Value 0xa1 0x81 0x0000 0x0700 0x0001 Description GET_CUR ZERO SELECTOR UNIT CONTROL | interface 0 The Length of Selector Control Parameter Block Size 1 Value 0xZZ Description "0x01" Value 0xa1 0x81 0x82 0x83 0x84 0x0000 0x0900 0x000C Description 5.5 Get Mixer Unit Control Request 5.5.1 Mixer Control Offset 0 1 Field bmRequestType bRequest Size 1 1 2 4 6 wValue wIndex wLength 2 2 2 GET_CUR GET_MIN GET_MAX GET_RES ZERO MIXER UNIT | interface 0 The Length of Mixer Control Parameter Block Parameter: Offset Field Size Value Description 0 bMixer 12 0xZZ The AK4571 returns 6 words of "0x0100" for GET_RES request, and returns the following 6 words for GET_CUR, GET_MIN, and GET_MAX requests. Offset 0 2 4 6 8 10 Value 0x0000 0x0000 0x0000 0x8000 0x8000 0x0000 Description Mic 1ch Mic 1ch DAC Lch DAC Lch DAC Rch DAC Rch ------------------- LineOut Lch: Lineout Rch: Lineout Lch: Lineout Rch: Lineout Lch: Lineout Rch: MS0153-E-03 0dB 0dB 0dB -127dB -127dB 0dB 2005/06 - 47 - ASAHI KASEI [AK4571] 5.6 Endpoint Control Request The ADC and DAC can independently operate at seven sampling frequencies. The sampling rate is set by a Set Endpoint Control Request. The AK4571 supports SET_CUR/GET_CUR for the bRequest field, but does not support GET_MIN, GET_MAX, or GET_RES for the bRequest field. 5.6.1 Set Endpoint Control Request Offset 0 1 2 Field bmRequestType bRequest wValue Size 1 1 2 Value 0x22 0x01 0x0100 4 wIndex 2 wLength 2 0x0081 0x0002 0x0003 6 Parameter: Offset Field 0 iSampleFreq SET_CUR Upper byte: SAMPLING_FREQ_CONTROL (0x01) Lower byte : zero Endpoint Address (0x81: A/D) Endpoint Address (0x02: D/A) The Length of Sampling Frequency Parameter Block Description The following seven values are valid. Others are invalid. 0x001F40 : 8kHz 0x002B11 : 11.025kHz 0x003E80 : 16kHz 0x005622 : 22.05kHz 0x007D00 : 32kHz 0x00AC44 : 44.1kHz 0x00BB80 : 48kHz The sampling rates of the ADC and DAC can be set independently. If the value entered is not one of the valid settings, the AK4571 ignores the entered value without returning STALL and keeps the previously entered value. 5.6.2 Size 3 Description Value 0xYYYYYY Get Endpoint Control Request for IN endpoint Offset 0 1 2 Field bmRequestType bRequest wValue Size 1 1 2 Value 0xA2 0x81 0x0100 4 wIndex 2 wLength 2 0x0081 0x0002 0x0003 6 Parameter: Offset Field 0 iSampleFreq Size 3 Value 0xYYYYYY Description GET_CUR Upper byte: SAMPLING_FREQ_CONTROL (0x01) Lower byte : zero Endpoint Address (0x81: A/D) Endpoint Address (0x02: D/A) The Length of Sampling Frequency Parameter Block Description The following seven values are valid. Others are invalid. 0x001F40 : 8kHz 0x002B11 : 11.025kHz 0x003E80 : 16kHz 0x005622 : 22.05kHz 0x007D00 : 32kHz 0x00AC44 : 44.1kHz ( default of this LSI ) 0x00BB80 : 48kHz MS0153-E-03 2005/06 - 48 - ASAHI KASEI [AK4571] 5.7 HID Related Request 5.7.1 Get Descriptor (HID/Report) Offset Field Size 0 BmRequestType 1 1 BRequest 1 2 wValue 2 4 6 wIndex wLength 2 2 Value 0x81 0x06 0x2100 0x2200 0x0003 0xZZZZ Description GET_DESCRIPTOR HID Descriptor Report Descriptor Interface Number (#3) Descriptor Length (ZZZZ is assigned by host) The AK4571 returns a HID Descriptor if wValue is 0x2100. The AK4571 returns the following 31 bytes if wValue is 0x2200. Report Descriptor Usage Page (Consumer) Usage (Consumer Control) Collection (Application) Logical Minimum (0) Logical Maximum (1) Usage (Volume Increment) Usage (Volume Decrement) Report Size (1) Report Count (2) Input (Data, Variable, Absolute, No_Wrap, No_Preferred) Usage (Mute) Report Count (1) Input (Data, Variable, Relative, No_Wrap, No_Preferred) Report Count (5) Input (Constant) End Collection 0x05, 0x0c 0x09, 0x01 0xA1, 0x01 0x15, 0x00 0x25, 0x01 0x09, 0xE9 0x09, 0xEA 0x75, 0x01 0x95, 0x02 0x81, 0x2A Data Length (1 bit) Number of Data (INC, DEC) 0x09, 0xE2 0x95, 0x01 0x81, 0x2E 0x95, 0x05 0x81, 0x01 0xC0 MS0153-E-03 2005/06 - 49 - ASAHI KASEI [AK4571] 5.7.2 Get Report Request Offset 0 1 Field bmRequestType BRequest Size 1 1 Value 0xA1 0x01 Description Class Specific Request GET_REPORT 2 4 6 Wvalue Windex WLength 2 2 2 0x0100 0x0003 0xZZZZ Report Type (IN) and Report ID Interface No (#3) Report Descriptor Length The AK4571 transmits one byte data that is the same format as Interrupt transaction. If it receives a request, it sends the internal register value that reflects the button-press state of OMUTE, INC and DEC pins. Note that the AK4571 does not clear the register after it receives this request. (It clears the register only on an Interrupt transfer) 5.8 String Related Request Offset 0 1 2 Field BmRequestType BRequest wValue 4 6 wIndex wLength Size 1 1 2 2 2 Value 0x80 0x06 0x03?? don't care 0xZZZZ Description GET_DESCRIPTOR (String) 0x03?? is assigned by host: 0x0300: LangID 0x0301: iManufacturer 0x0302: iProduct Descriptor Length (ZZZZ is assigned by host) The AK4571 returns String Descriptor that is specified in wValue. MS0153-E-03 2005/06 - 50 - ASAHI KASEI [AK4571] 6 System Block Diagram Figure 14 shows the system block diagram when a 1Kbit EEPROM is used. VD 0.1u 0.1u 47K 0.1u 47K 47K 0.1u 47K VD 1.5K 47K DP DN 3.3n 4.7 + TEST3 0.1 TEST2 MSTAT LFLT_SYS CS RBFO ROUT RBFI LOUT + 4.7 AGND + VA 6.8n 6.8n 0.1 VRAD LBFO LBFI AMP2I VCOM AMP1O 120k MICIN MICBIAS LFLT_48K + VRDA TESTMODE1 AMP2O LFLT_44K 4.7 EPDI EPAO SK TESTMODE3 TESTMODE2 STBY EMSW 22n EPEN XTALIN 10p 120k EPSEL EPSW *) 2.7k TEST1 IMUTE 12MHz INC DGND BGND XTALOUT 10p*) DEC OMUTE SUSN RSTN 1 0.1 + 4.7 0.1 4.7 0.1 1 Cb Cb 300 1 Rb 10 1n + 0.1 1 MIC Rb 1 <example> Gain=19dB, fc=94Hz Rb: 360K Cb: 4.7n 10K< 10K< 4.7K/2.2K *) 10pF is recommended to get a stable analog performance. Figure 14 System Block Diagram MS0153-E-03 2005/06 - 51 - ASAHI KASEI [AK4571] 7 Package 48pin LQFP(Unit:mm) 1.70Max 9.0 0.2 0.13 0.13 7.0 1.40 0.05 25 24 48 13 7.0 37 1 9.0 0.2 36 12 0.16 0.07 0.5 0.22 0.08 0.10 M 0 10 0.10 0.5 0.2 MS0153-E-03 2005/06 - 52 - ASAHI KASEI [AK4571] 8 Marking AK4571VQ XXXXXXX 1 1) Pin #1 indication 2) Date Code: XXXXXXX (7 digits) 3) Marking Code: AK4571VQ 4) Asahi Kasei Logo MS0153-E-03 2005/06 - 53 - ASAHI KASEI [AK4571] IMPORTANT NOTICE * These products and their specifications are subject to change without notice. Before considering any use or application, consult the Asahi Kasei Microsystems Co., Ltd. (AKM) sales office or authorized distributor concerning their current status. * AKM assumes no liability for infringement of any patent, intellectual property, or other right in the application or use of any information contained herein. * Any export of these products, or devices or systems containing them, may require an export license or other official approval under the law and regulations of the country of export pertaining to customs and tariffs, currency exchange, or strategic materials. * AKM products are neither intended nor authorized for use as critical components in any safety, life support, or other hazard related device or system, and AKM assumes no responsibility relating to any such use, except with the express written consent of the Representative Director of AKM. As used here: (a) A hazard related device or system is one designed or intended for life support or maintenance of safety or for applications in medicine, aerospace, nuclear energy, or other fields, in which its failure to function or perform may reasonably be expected to result in loss of life or in significant injury or damage to person or property. (b)A critical component is one whose failure to function or perform may reasonably be expected to result, whether directly or indirectly, in the loss of the safety or effectiveness of the device or system containing it, and which must therefore meet very high standards of performance and reliability. * It is the responsibility of the buyer or distributor of an AKM product who distributes, disposes of, or otherwise places the product with a third party to notify that party in advance of the above content and conditions, and the buyer or distributor agrees to assume any and all responsibility and liability for and hold AKM harmless from any and all claims arising from the use of said product in the absence of such notification. MS0153-E-03 2005/06 - 54 -