Features * Read Access Time - 200 ns * Automatic Page Write Operation * * * * * * * * - Internal Address and Data Latches for 256 Bytes - Internal Control Timer Fast Write Cycle Time - Page Write Cycle Time - 10 ms Maximum - 1 to 256 Byte Page Write Operation Low Power Dissipation - 50 mA Active Current Hardware and Software Data Protection DATA Polling for End of Write Detection High Reliability CMOS Technology - Endurance: 10,000 Cycles - Data Retention: 10 Years Single 5V 10% Supply CMOS and TTL Compatible Inputs and Outputs JEDEC Approved Byte-Wide Pinout 4-Megabit (512K x 8) Paged Parallel EEPROMs AT28C040 1. Description The AT28C040 is a high-performance electrically erasable and programmable readonly memory (EEPROM). Its 4 megabits of memory is organized as 524,288 words by 8 bits. Manufactured with Atmel's advanced nonvolatile CMOS technology, the device offers access times to 200 ns with power dissipation of just 440 mW. The AT28C040 is accessed like a static RAM for the read or write cycle without the need for external components. The device contains a 256-byte page register to allow writing of up to 256 bytes simultaneously. During a write cycle, the address and 1 to 256 bytes of data are internally latched, freeing the address and data bus for other operations. Following the initiation of a write cycle, the device will automatically write the latched data using an internal control timer. The end of a write cycle can be detected by Data Polling of I/O7. Once the end of a write cycle has been detected, a new access for a read or write can begin. Atmel's AT28C040 has additional features to ensure high quality and manufacturability. The device utilizes internal error correction for extended endurance and improved data retention characteristics. An optional software data protection mechanism is available to guard against inadvertent writes. The device also includes an extra 256 bytes of EEPROM for device identification or tracking. 0542F-PEEPR-2/09 2. Pin Configurations Pin Name Function A0 - A18 Addresses CE Chip Enable OE Output Enable WE Write Enable I/O0 - I/O7 Data Inputs/Outputs NC No Connect 32-lead Flatpack - Top View A18 A16 A15 A12 A7 A6 A5 A4 A3 A2 A1 A0 I/O0 I/O1 I/O2 GND 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 32 31 30 29 28 27 26 25 24 23 22 21 20 19 18 17 VCC WE A17 A14 A13 A8 A9 A11 OE A10 CE I/O7 I/O6 I/O5 I/O4 I/O3 44-lead LCC - Top View 39 38 37 36 35 34 33 32 31 30 29 18 19 20 21 22 23 24 25 26 27 28 7 8 9 10 11 12 13 14 15 16 17 A13 A8 A9 A11 NC NC NC NC OE A10 CE A0 I/O0 I/O1 I/O2 VSS NC I/O3 I/O4 I/O5 I/O6 I/O7 A12 A7 A6 A5 NC NC NC A4 A3 A2 A1 6 5 4 3 2 1 44 43 42 41 40 A15 A16 A18 NC NC NC VCC WE NC A17 A14 2.1 2.2 2 AT28C040 0542F-PEEPR-2/09 AT28C040 3. Block Diagram 4. Absolute Maximum Ratings* Temperature Under Bias................................ -55C to +125C Storage Temperature ..................................... -65C to +150C All Input Voltages (including NC pins) with Respect to Ground ...................................-0.6V to +6.25V All Output Voltages with Respect to Ground .............................-0.6V to VCC + 0.6V *NOTICE: Stresses beyond those listed under "Absolute Maximum Ratings" may cause permanent damage to the device. This is a stress rating only and functional operation of the device at these or any other conditions beyond those indicated in the operational sections of this specification is not implied. Exposure to absolute maximum rating conditions for extended periods may affect device reliability. Voltage on OE and A9 with Respect to Ground ...................................-0.6V to +13.5V 3 0542F-PEEPR-2/09 5. Device Operation 5.1 Read The AT28C040 is accessed like a static RAM. When CE and OE are low and WE is high, the data stored at the memory location determined by the address pins is asserted on the outputs. The outputs are put in the high impedance state when either CE or OE is high. This dual-line control gives designers flexibility in preventing bus contention in their systems. 5.2 Byte Write A low pulse on the WE or CE input with CE or WE low (respectively) and OE high initiates a write cycle. The address is latched on the falling edge of CE or WE, whichever occurs last. The data is latched by the first rising edge of CE or WE. Once a byte write has been started, it will automatically time itself to completion. Once a programming operation has been initiated and for the duration of tWC, a read operation will effectively be a polling operation. 5.3 Page Write The page write operation of the AT28C040 allows 1 to 256 bytes of data to be written into the device during a single internal programming period. A page write operation is initiated in the same manner as a byte write; the first byte written can then be followed by 1 to 255 additional bytes. Each successive byte must be written within 150 s (tBLC) of the previous byte. If the tBLC limit is exceeded, the AT28C040 will cease accepting data and commence the internal programming operation. All bytes during a page write operation must reside on the same page as defined by the state of the A8 - A18 inputs. For each WE high to low transition during the page write operation, A8 - A18 must be the same. The A0 to A7 inputs specify which bytes within the page are to be written. The bytes may be loaded in any order and may be altered within the same load period. Only bytes which are specified for writing will be written; unnecessary cycling of other bytes within the page does not occur. 5.4 Data Polling The AT28C040 features Data Polling to indicate the end of a write cycle. During a byte or page write cycle an attempted read of the last byte written will result in the complement of the written data to be presented on I/O7. Once the write cycle has been completed, true data is valid on all outputs, and the next write cycle may begin. Data Polling may begin at anytime during the write cycle. 5.5 Toggle Bit In addition to Data Polling, the AT28C040 provides another method for determining the end of a write cycle. During the write operation, successive attempts to read data from the device will result in I/O6 toggling between one and zero. Once the write has completed, I/O6 will stop toggling and valid data will be read. Reading the toggle bit may begin at any time during the write cycle. 5.6 Data Protection If precautions are not taken, inadvertent writes may occur during transitions of the host system power supply. Atmel(R) has incorporated both hardware and software features that will protect the memory against inadvertent writes. 4 AT28C040 0542F-PEEPR-2/09 AT28C040 5.6.1 Hardware Protection Hardware features protect against inadvertent writes to the AT28C040 in the following ways: (a) VCC sense - if VCC is below 3.8V (typical) the write function is inhibited; (b) VCC power-on delay - once VCC has reached 3.8V the device will automatically time out 5 ms (typical) before allowing a write: (c) write inhibit - holding any one of OE low, CE high or WE high inhibits write cycles; (d) noise filter - pulses of less than 15 ns (typical) on the WE or CE inputs will not initiate a write cycle. 5.6.2 Software Data Protection A software controlled data protection feature has been implemented on the AT28C040. When enabled, the software data protection (SDP), will prevent inadvertent writes. The SDP feature may be enabled or disabled by the user; the AT28C040 is shipped from Atmel with SDP disabled. SDP is enabled when the host system issues a series of three write commands; three specific bytes of data are written to three specific addresses (refer to Software Data Protection Algorithm). After writing the 3-byte command sequence and after tWC, the entire AT28C040 will be protected against inadvertent write operations. It should be noted that once protected, the host can still perform a byte or page write to the AT28C040. To do so, the same 3-byte command sequence used to enable SDP must precede the data to be written. Once set, SDP will remain active unless the disable command sequence is issued. Power transitions do not disable SDP, and SDP will protect the AT28C040 during power-up and power-down conditions. All command sequences must conform to the page write timing specifications. The data in the enable and disable command sequences is not written to the device, and the memory addresses used in the sequence may be written with data in either a byte or page write operation. After setting SDP, any attempt to write to the device without the 3-byte command sequence will start the internal write timers. No data will be written to the device; however, for the duration of tWC, read operations will effectively be polling operations. 5.7 Device Identification An extra 256 bytes of EEPROM memory are available to the user for device identification. By raising A9 to 12V 0.5V and using address locations 7FF80H to 7FFFFH, the bytes may be written to or read from in the same manner as the regular memory array. 5.8 Optional Chip Erase Mode The entire device can be erased using a 6-byte software erase code. Please see Software Chip Erase application note for details. 5 0542F-PEEPR-2/09 6. DC and AC Operating Range AT28C040-20 Operation Read Program Industrial -40C - 85C -40C - 85C Extended -55C - 125C -40C - 85C 5V 10% 5V 10% Operating Temperature (Case) VCC Power Supply 7. Operating Modes Mode CE OE WE I/O Read VIL VIL VIH DOUT Write(2) VIL VIH VIL DIN Write Inhibit X X VIH Write Inhibit X VIL X Output Disable X VIH X Notes: High Z 1. X can be VIL or VIH. 2. Refer to AC Programming Waveforms. 8. DC Characteristics Symbol Parameter Condition ILI Input Load Current ILO Max Units VIN = 0V to VCC + 1V 10 A Output Leakage Current VI/O = 0V to VCC 10 A ICC VCC Active Current f = 5 MHz; IOUT = 0 mA 50 mA VIL Input Low Voltage 0.8 V VIH Input High Voltage VOL Output Low Voltage IOL = 2.1 mA VOH1 Output High Voltage IOH = -400 A 2.4 V VOH2 Output High Voltage CMOS IOH = -100 A; VCC = 4.5V 4.2 V 6 Min 2.0 V 0.45 V AT28C040 0542F-PEEPR-2/09 AT28C040 9. AC Read Characteristics AT28C040-20 Symbol Parameter Min tACC Address to Output Delay tCE(1) tOE(2) tDF(3)(4) CE to Output Delay tOH Max Units 200 ns 200 ns OE to Output Delay 0 55 ns CE or OE to Output Float 0 55 ns Output Hold from OE, CE or Address, whichever occurred first 0 ns 10. AC Read Waveforms(1)(2)(3)(4) Notes: 1. CE May be delayed up to tACC - tCE after the address transition without impact on tACC. 2. OE may be delayed up to tCE - tOE after the falling edge of CE without impact on tCE or by tACC - tOE after an address change without impact on tACC. 3. tDF is specified from OE or CE, whichever occurs first (CL = 5 pF). 4. This parameter is characterized and is not 100% tested. 11. Input Test Waveforms and Measurement Level tR, tF < 5 ns 12. Output Test Load 13. Pin Capacitance f = 1 MHz, T = 25C(1) Symbol CIN COUT Note: Typ Max Units Conditions 4 10 pF VIN = 0V 8 12 pF VOUT = 0V 1. This parameter is characterized and is not 100% tested. 7 0542F-PEEPR-2/09 14. AC Write Characteristics Symbol Parameter Min Max Units tAS, tOES Address, OE Set-up Time 0 ns tAH Address Hold Time 50 ns tCS Chip Select Set-up Time 0 ns tCH Chip Select Hold Time 0 ns tWP Write Pulse Width (WE or CE) 100 ns tDS Data Set-up Time 50 ns tDH, tOEH Data, OE Hold Time 0 ns 15. AC Write Waveforms 15.1 WE Controlled 15.2 CE Controlled 8 AT28C040 0542F-PEEPR-2/09 AT28C040 16. Page Mode Characteristics Symbol Parameter Min Max Units tWC Write Cycle Time 10 ms tAS Address Set-up Time 0 ns tAH Address Hold Time 50 ns tDS Data Set-up Time 50 ns tDH Data Hold Time 0 ns tWP Write Pulse Width 100 ns tBLC Byte Load Cycle Time tWPH Write Pulse Width High 150 50 s ns 17. Page Mode Write Waveforms(1)(2) Notes: 1. A8 through A18 must specify the page address during each high to low transition of WE (or CE). 2. OE must be high only when WE and CE are both low. 9 0542F-PEEPR-2/09 18. Software Data Protection Enable Algorithm(1) Notes: 19. Software Data Protection Disable Algorithm(1) LOAD DATA AA TO ADDRESS 5555 LOAD DATA AA TO ADDRESS 5555 LOAD DATA 55 TO ADDRESS 2AAA LOAD DATA 55 TO ADDRESS 2AAA LOAD DATA A0 TO ADDRESS 5555 LOAD DATA 80 TO ADDRESS 5555 WRITES ENABLED(2) LOAD DATA XX TO ANY ADDRESS(4) LOAD DATA AA TO ADDRESS 5555 LOAD LAST BYTE TO LAST ADDRESS LOAD DATA 55 TO ADDRESS 2AAA ENTER DATA PROTECT STATE 1. Data Format: I/O7 - I/O0 (Hex); Address Format: A14 - A0 (Hex). 2. Write Protect state will be activated at end of write even if no other data is loaded. 3. Write Protect state will be deactivated at end of write period even if no other data is loaded. 4. 1 to 256 bytes of data are loaded. LOAD DATA 20 TO ADDRESS 5555 EXIT DATA PROTECT STATE(3) LOAD DATA XX TO ANY ADDRESS(4) LOAD LAST BYTE TO LAST ADDRESS 20. Software Protected Program Cycle Waveform(1)(2)(3) Notes: 1. A0 - A14 must conform to the addressing sequence for the first 3 bytes as shown above. 2. After the command sequence has been issued and a page write operation follows, the page address inputs (A8 - A18) must be the same for each high to low transition of WE (or CE). 3. OE must be high only when WE and CE are both low. 10 AT28C040 0542F-PEEPR-2/09 AT28C040 21. Data Polling Characteristics(1) Symbol Parameter tDH Data Hold Time tOEH OE Hold Time Typ Max ns 10 ns OE to Output Delay tWR Write Recovery Time Units 10 (2) tOE Notes: Min ns 0 ns 1. These parameters are characterized and not 100% tested. 2. See AC Read Characteristics. 22. Data Polling Waveforms 23. Toggle Bit Characteristics(1) Symbol Parameter tDH Data Hold Time 10 ns tOEH OE Hold Time 10 ns tOE OE to Output Delay(2) tOEHP OE High Pulse tWR Write Recovery Time Notes: Min Typ Max Units ns 150 ns 0 ns 1. These parameters are characterized and not 100% tested. 2. See AC Read Characteristics. 24. Toggle Bit Waveforms(1)(2)(3) Notes: 1. Toggling either OE or CE or both OE and CE will operate toggle bit. 2. Beginning and ending state of I/O6 will vary. 3. Any address location may be used but the address should not vary. 11 0542F-PEEPR-2/09 25. Ordering Information 25.1 Standard Packaging ICC (mA) tACC (ns) Active 50 200 50 Note: Ordering Code Package Operation Range AT28C040-20FI 32F AT28C040-20LI 44L Industrial (-40 to 85C) AT28C040-20FI SL703 32F AT28C040-20LI SL703 44L Extended (See DC and AC Operating Range Table) 1. SL703 requires testing to Mil-883 standards; SL703 is marked on the package. Package Type 32F 32-Lead, Non-Windowed, Ceramic Bottom-Brazed Flat Package (Flatpack) 44L 44-Pad, Non-Windowed, Ceramic Leadless Chip Carrier (LCC) Options Blank 12 Standard Device: Endurance = 10K Write Cycles; Write Time = 10 ms AT28C040 0542F-PEEPR-2/09 AT28C040 26. Packaging Information 26.1 32F - Flatpack Dimensions in Millimeters and (Inches). Controlling dimension: Inches. JEDEC Outline MO-115 AA PIN #1 ID 9.40(0.370) 6.86(0.270) 0.51(0.020) 0.38(0.015) 21.08(0.830) 20.60(0.811) 1.27(0.050) BSC 1.14(0.045) MAX 12.40(0.488) 11.99(0.472) 3.05(0.120) 2.49(0.098) 0.18(0.007) 0.10(0.004) 10.36(0.408) 9.02(0.355) 1.14(0.045) 0.66(0.026) 1.83(0.072) 0.76(0.030) 10/21/03 R 2325 Orchard Parkway San Jose, CA 95131 TITLE 32F, 32-lead, Non-windowed, Ceramic Bottom-brazed Flat Package (FlatPack) DRAWING NO. REV. 32F B 13 0542F-PEEPR-2/09 26.2 44L - LCC Dimensions in Millimeters and (Inches) Controlling dimension: Inches MIL-STD-1835 C-5 16.81(0.662) 16.26(0.640) 2.74(0.108) 2.16(0.085) 16.81(0.662) 16.26(0.640) PIN 1 2.41(0.095) 1.91(0.075) 1.40(0.055) 1.14(0.045) 2.03(0.080) 1.40(0.055) INDEX CORNER 0.635(0.025) X 45 0.381(0.015) 0.305(0.012) RADIUS 0.178(0.007) 12.70(0.500) BSC 0.737(0.029) 0.533(0.021) 1.27(0.050) TYP 1.02(0.040) X 45 12.70(0.500) BSC 2.16(0.085) 1.65(0.065) 04/11/01 R 14 2325 Orchard Parkway San Jose, CA 95131 TITLE 44L, 44-pad (0.600" Wide), Non-windowed, Ceramic Lid, Leadless Chip Carrier (LCC) DRAWING NO. REV. 44L A AT28C040 0542F-PEEPR-2/09 Headquarters International Atmel Corporation 2325 Orchard Parkway San Jose, CA 95131 USA Tel: 1(408) 441-0311 Fax: 1(408) 487-2600 Atmel Asia Unit 1-5 & 16, 19/F BEA Tower, Millennium City 5 418 Kwun Tong Road Kwun Tong, Kowloon Hong Kong Tel: (852) 2245-6100 Fax: (852) 2722-1369 Atmel Europe Le Krebs 8, Rue Jean-Pierre Timbaud BP 309 78054 Saint-Quentin-enYvelines Cedex France Tel: (33) 1-30-60-70-00 Fax: (33) 1-30-60-71-11 Atmel Japan 9F, Tonetsu Shinkawa Bldg. 1-24-8 Shinkawa Chuo-ku, Tokyo 104-0033 Japan Tel: (81) 3-3523-3551 Fax: (81) 3-3523-7581 Technical Support p_eeprom@atmel.com Sales Contact www.atmel.com/contacts Product Contact Web Site www.atmel.com Literature Requests www.atmel.com/literature Disclaimer: The information in this document is provided in connection with Atmel products. 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