Clock Synthesizer with Differential CPU Outpu
ts
CY28346
-2
Cypress Semiconductor Corporation 3901 North First Street San Jose,CA 95134 408-943-2600
Document #: 38-07509 Rev. *A Revised June 5, 2003
Features
Compliant with Intel® CK 408 Mobile Clock Synthesizer
specifications
3.3V power supply
3 differential CPU clocks
10 copies of PCI clocks
5/6 copies of 3V66 clocks
SMBus support with Read Back capabilities
Spread Spectrum electromagnetic interference (EMI)
reduction
Dial-a-Frequency features
Dial-a-dB™ f eatures
Extended operating temperature range, 0°C to 85°C
56-pin TSSOP packages
Note:
1. TCLK is a test clock driven on the XTAL_IN input during test mode. M = driven to a level between 1.0V and 1.8V. If the S2 pin is at a M level during power-up,
a 0 state will be latched into the devices internal state register.
Table 1. Frequency Tabl e [1]
S2 S1 S0 CPU
(0:2) 3V66 66BUFF(0:2)/
3V66(0:4) 66IN/
3V66-5 PCIF/PCI REF USB/
DOT
1 0 0 66M 66M 66IN 66-MHz clock input 66IN/2 14.318M 48M
1 0 1 100M 66M 66IN 66-MHz clock input 66IN/2 14.318M 48M
1 1 0 200M 66M 66IN 66-MHz clock input 66IN/2 14.318M 48M
1 1 1 133M 66M 66IN 66-MHz clock input 66IN/2 14.318M 48M
0 0 0 66M 66M 66M 66M 33 M 14.318M 48 M
0 0 1 100M 66M 6 6M 66M 33 M 14.3 18M 48M
0 1 0 200M 66M 6 6M 66M 33 M 14.3 18M 48M
0 1 1 133M 66M 6 6M 66M 33 M 14.3 18M 48M
M 0 0 Hi-Z Hi-Z Hi-Z Hi-Z Hi-Z Hi-Z Hi-Z
M 0 1 TCLK/2 TCLK/4 TCLK/4 TCLK/4 TCLK/8 TCLK TCLK/2
PLL1
PLL2
/2
WD
Logic
Power
Up Logic
XIN
XOUT
CPU_STP#
IREF
VSSIREF
S(0:2)
MULT0
VTT_PWRGD#
PCI_STP#
PD#
SDATA
SCLK
VDDA 66B[0:2]/3V66[2:4
]
48M_DOT
48M_USB
PCI_F(0:2)
PCI(0:6)
3V66_1/VCH
3V66_0
CPUC(0:2)
CPUT(0:2)
REF
66IN/3V66-5
I2C
Logic
VDD
XIN
XOUT
VSS
PCIF0
PCIF1
PCIF2
VDD
VSS
PCI0
PCI1
PCI2
PCI3
VDD
VSS
PCI4
PCI5
PCI6
VDD
VSS
66B0/3V66_2
66B1/3V66_3
66B2/3V66_4
66IN/3V66_5
PD#
VDDA
VSSA
VTT_PWRGD#
REF
S1
S0
CPU_STP#
CPUT0
CPUC0
VDD
CPUT1
CPUC1
VSS
VDD
CPUT2
CPUC2
MULT0
IREF
VSSIREF
S2
48M_USB
48M_DOT
VDD
VSS
3V66_1/VCH
PCI_STP#
3V66_0
VDD
VSS
SCLK
SDATA
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
56
55
54
53
52
51
50
49
48
47
46
45
44
43
42
41
40
39
38
37
36
35
34
33
32
31
30
29
CY28346-2
Block Diagram Pin Configurat ion
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Document #: 38-07509 Rev. *A Page 2 of 20
Pin Description
Pin Name PWR I/O Description
2XIN VDDIOscillator Buffer Input. Connect to a crystal or to an external clock.
3XOUT VDDOOscillator Buffer Output. Connect to a cryst al. Do not connect when an
external clock is applied at XIN.
52, 51, 4 9, 48 ,
45, 44 CPUT(0:2),
CPUC(0:2) VDD O Differential host output clock pairs. See Table 1 for frequencies and
functionality.
10, 11, 12, 13,
16, 17, 18 PCI(0:6) VDDP O PCI clock outputs. Are synchronous to 66IN or 3V66 clock. See Table 1.
5, 6, 7 PCIF (0:2) VDD O 33-MHz PCI clocks, which are ÷2 copies of 66IN or 3V66 clocks, may
be free running (not stopped when PCI_STP# is asserted LOW) or
may be stoppable depending on the programming of SMBus
register Byte3, Bits (3:5).
56 REF VDD O Buffered output copy of the device’s XIN clock.
42 IREF VDD I Current reference programming input for CPU buffers. A resistor is
connected between this pin and VSSIREF.
28 VTT_PWRGD# VDD I Qualify ing inp ut that latches S(0:2) a nd MULT0. When th is in put i s at
a logic low, the S(0:2) and MULT0 are latched.
39 48M_USB VDD48 O Fixed 48-MHz USB clock outputs.
38 48M_DOT VDD48 O Fixed 48-MHZ DOT clock outputs.
33 3V66_0 VDD O 3.3V 66-MHz fixed frequency clock.
35 3V66_1/VCH VDD O 3.3V clock selec table with SMBus byte0, Bit5, when Byte5, Bit5.
When Byte 0 Bit 5 is at a logic 1, then this pin is a 48M output clock. When
byte0, Bit5 is a logic 0, then this is a 66M output clock (default).
25 PD# VDD I
PU This pin is a power-down mode pin. A logic LOW level causes the
device to enter a p ower-down state. All intern al logic is turned off ex cept
for the SMBus logic. All output buffers are stopped.
43 MULT0 VDD I
PU Programming input selection for CPU clock current multiplier.
55, 54 S(0,1) I I Frequency select inputs. See Table 1
29 SDATA I I Serial data input. Conforms to the SMBus specification of a Slave
Receive/T ra nsmit device . It is an input when receiving dat a. It is an open
drain output when acknowledging or transmitting data.
30 SCLK I I Serial clock input. Conforms to the SMBus specification.
40 S2 VDD I
TFrequency select input. See Table 1. This is a Tri-level input that is
driven HIGH, LOW, or driven to a intermediate level.
34 PCI_STP# VDD I
PU PCI clock disable input. When asserted LOW, PCI (0:6) clocks are
synchronously disabled in a LOW state. This pin does not effect PCIF
(0:2) clocks’ outputs if they are programmed to be PCIF clocks via the
device’s SMBus interface.
53 CPU_STP# VDD I
PU CPU clock d isab le input. W hen as serted LOW, CPUT (0:2) cl ocks are
synchronously di sabled in a HIGH state and CPUC(0:2) clocks are
synchronously disabled in a LOW state.
24 66IN/3V66_5 VDD I/O Input connection for 66CLK(0:2) output clock buffers if S2 = 1, or
output clock for fixed 66-MHz clock if S2 = 0. See Table 1.
21, 22, 23 66B(0:2)/
3V66(2:4) VDD O 3.3V clock ou tputs . These cl ocks are buffer ed copies of the 66IN clock
or fixed at 66 MHz. See Table 1.
1, 8, 14, 19, 32,
37, 46, 50 VDD PWR 3.3V power supply.
4, 9, 15, 20, 27,
31, 36, 47 VSS PWR Common ground.
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Seria l Data Interfac e
To enh ance the f lexibility and function of th e clock sy nthesizer ,
a two-signal serial interface is provided. Through the Serial
Data Interface, various device functions, such as individual
clock output buffers, can be individually enabled or disabled.
The registers associated with the Serial Data Interface
initial izes to t heir defaul t setting upon power-up, and theref ore
use of this interface is optional. Clock device register changes
are normally made upon system initialization, if any are
required. The interface can also be used during system
operation for power management functions.
Data Protocol
The clock driver serial protocol accepts block write and block
read operations from the controller. For block write/read
operation, the bytes must be accessed in sequential order
from lowest to highest byte (most significant bit first) with the
ability to stop after any complete byte has been transferred.
The block write and block read protocol is outlined in Table 2.
The slave receiver address is 11010010 (D2h).
41 VSSIREF PWR Current reference programming input for CPU buffers. A resistor is
connected between this pin and IREF. This pin should also be returned
to device VSS.
26 VDDA PWR Analog power input. Used for PLL and internal analog circuits. It is also
specifically used to detect and determine when power is at an acceptable
level to enable the device to operate.
Pin Description (continued)
Pin Name PWR I/O Description
Table 2. Block Read and Block Write Protocol
Block Write Protocol Block Read Protocol
Bit Description Bit Description
1 Start 1 Start
2:8 Slave address – 7 bits 2:8 Slave address – 7 bits
9 Writ e = 0 9 Write = 0
10 Acknowl edg e from sl ave 10 Ack no wled ge from slav e
11:18 Command Code – 8 bit
‘00000000’ stands for block operation 11:18 Command Code – 8 bit
‘00000000’ stands for block operation
19 Acknowl edg e from sl ave 19 Ack no wled ge from slav e
20:27 Byte Count – 8 bits 20 Repeat start
28 Acknowledge from slave 21:27 Slave address – 7 bits
29:36 Data byte 1 – 8 bits 28 Read = 1
37 Acknowl edg e from sl ave 29 Ack no wled ge from slav e
38:45 Data byte 2 – 8 bits 30:37 Byte count from slave – 8 bits
46 Acknowledge from slave 38 Acknowledge
.... ...................... 39:46 Data byte from slave – 8 bits
.... Data Byte (N–1) –8 bits 47 Acknowledge
.... Acknowledge from slave 48:55 Data byte from slave – 8 bits
.... Data Byte N –8 bits 56 Acknowledge
.... Acknowledge from slave .... Data bytes from slave/Acknowledge
.... Stop .... Data byte N from slave – 8 bits
.... Not Acknowledge
.... Stop
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Byte 0: CPU Clock Register
Bit @Pup Name Description
7 0 Spread Spectrum Enable, 0 = Spread Off, 1 = Spread On. This is a Read and Write control bit.
60 CPU clock Power-down Mode Select.
0 = Drive CPUT(0:2) to 4 or 6 IREF and drive CPUC(0:2) to low when PD# is asserted LOW.
1 = Three- sta te all C PU outpu t s. Thi s is only applic able w hen PD# is LOW. It is not applica ble to
CPU_STP#.
503V66_1/VCH 3V66_1/VCH fr eque ncy Sel ect, 0 = 66M selected, 1 = 48M s elected
This is a Read and Write control bit.
4 Pin 53 CPUT,CPUC CPU_STP#. Reflects the c urren t val ue of the external CPU_STP# (pin 53) This bit is Read -onl y.
3Pin 34 PCI Reflect s the current val ue of the intern al PCI_ST P# func tio n when read. Inte rnal ly PCI_STP# is
a logical AND function of the internal SMBus register bit and the external PCI_STP# pin.
2 Pin 40 Frequency Select Bit 2. Reflects the value of SEL2 (pin 40). This bit is Read-only.
1 Pin 55 Frequency Select Bit 1. Reflects the value of SEL1 (pin 55). This bit is Read-only.
0 Pin 54 Frequency Select Bit 0. Reflects the value of SEL0 (pin 54). This bit is Read-only.
Byte 1: CPU Clock Register
Bit @Pup Name Description
7 Pin 43 MULT0 MULT0 (Pin 43) Value. This bit is Read-only.
6 0 CPU_STP# Contro ls func tional ity of CPU T/C(0:2) ou tput s whe n CPU_STP# is asserted . 0 = Drive C PUT(0:2) to
4 or 6 IREF and drive CPUC(0:2) to low when CPU_STP# asserted LOW. 1 = Three-state all CPU
outputs. This bit will override Byte0, Bit6 such that even if it is a 0, when PD# goes low the CPU outputs
will be three-stated.
50 CPUT2
CPUC2 Controls CPU2 functionality when CPU_STP# is asserted LOW
1 = Free Running, 0 = Stopped LOW with CPU_STP# asserted LOW
This is a Read and Write control bit.
40 CPUT1
CPUC1 Controls CPU1 functionality when CPU_STP# is asserted LOW
1 = Free Running, 0 = Stopped LOW with CPU_STP# asserted LOW
This is a Read and Write control bit.
30 CPUT0
CPUC0 Controls CPUT0 functionality when CPU_STP# is asserted LOW
1 = Free Running, 0 = Stopped LOW with CPU_STP# asserted LOW
This is a Read and Write control bit.
21 CPUT2
CPUC2 CPUT/C2 Output Control, 1 = enabled, 0 = disable HIGH and CPUC2 disables LOW
This is a Read and Write control bit.
11 CPUT1
CPUC1 CPUT/C1 Output Control, 1 = enabled, 0 = disable HIGH and CPUC1 disables LOW
This is a Read and Write control bit.
01 CPUT0
CPUC0 CPUT/C0 Output Control, 1 = enabled, 0 = disable HIGH and CPUC0 disables LOW
This is a Read and Write control bit.
Byte 2: PCI Clock Control Register (all bits are read and write functional)
Bit @Pup Name Description
7 0 REF REF Output Control. 0 = high strength, 1 = low strength
6 1 PCI6 PCI6 Output Control. 1 = enabled, 0 = forced LOW
5 1 PCI5 PCI5 Output Control. 1 = enabled, 0 = forced LOW
4 1 PCI4 PCI4 Output Control. 1 = enabled, 0 = forced LOW
3 1 PCI3 PCI3 Output Control. 1 = enabled, 0 = forced LOW
2 1 PCI2 PCI2 Output Control. 1 = enabled, 0 = forced LOW
1 1 PCI1 PCI1 Output Control. 1 = enabled, 0 = forced LOW
0 1 PCI0 PCI0 Output Control. 1 = enabled, 0 = forced LOW
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Byte 3: PCIF Clock and 48M Control Register (all bits are read and write functional)
Bit @Pup Name Description
7 1 48M_DOT 48M_DOT Output Control,1 = enabled, 0 = forced LOW
6 1 48M_USB 48M_USB Output Control,1 = enabled, 0 = forced LOW
5 0 PCIF2 PCI_STP#, control of PCIF2.
0 = Free Running, 1 = Stopped when PCI_STP# is LOW
4 0 PCIF1 PCI_STP#, control of PCIF1.
0 = Free Running, 1 = Stopped when PCI_STP# is LOW
3 0 PCIF0 PCI_STP#, control of PCIF0.
0 = Free Running, 1 = Stopped when PCI_STP# is LOW
2 1 PCIF2 PCIF2 Output Control. 1=running, 0=forced LOW
1 1 PCIF1 PCIF1 Output Control. 1= running, 0=forced LOW
0 1 PCIF0 PCIF0 Output Control. 1= running, 0=forced LOW
Byte 4: DRCG Control Register(all bits are read and write functional )
Bit @Pup Name Description
7 0 SS2 Spread Spectrum control bit (0 = down spread, 1 = center spread)
60 Reserved
5 1 3V66_0 3V66_0 Output Enabled. 1 = enabled, 0 = disabled
4 1 3V66_1/VCH 3V66 _1/VCH Output Enable. 1 = enabled, 0 = disabled
3 1 3V66_5 3V66_5 Output Enable. 1 = enabled, 0 = disabled
2 1 66B2/3V66_4 66B2/3V66_4 Output Enabled. 1 = enabled, 0 = disabled
1 1 66B1/3V66_3 66B1/3V66_3 Output Enabled. 1 = enabled, 0 = disabled
0 1 66B0/3V66_2 66B0/3V66_2 Output Enabled. 1 = enabled, 0 = disabled
Byte 5: Clock Control Register (all bits are read and write functional)
Bit @Pup Name Description
7 0 SS1 Spread Spectrum control bit
6 1 SS0 Spread Spectrum control bit
5 0 66IN to 66M delay Control MSB
4 0 66IN to 66M delay Control LSB,
30 Reserved
2 0 48M_DOT edge rate control. When set to 1, the edge is slowed by 15%.
10 Reserved
0 0 USB edge rate control. When set to 1, the edge is slowed by 15%
Byte 6: Silicon Signature Register[2] (all bits are read-only)
Bit @Pup Name Description
70
60
50
41
3 0 Vendor Code, 011 = IMI
20
11
01
Note:
2. When writing to this register the device will acknowled ge the write operation , but the data itself will be ignored.
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Dial-a-Frequency Feature
SMBus D ial-a-Frequenc y feature is availabl e in this device via
Byte8 and Byte9. Se e our App Note AN-0025 for details on our
Dial-a-Frequency feature.
P is a large v alue PLL const ant that depen ds on the frequency
selection achieved through the hardware selectors (S1, S0).
P value may be determined from Table 3.
Dial-a-dB Features
SMBus Dial-a-dB feature is available in this device via Byte8
and Byte9.
Spread Spectrum Clock Generation (SSCG)
Spread Spectrum is a modulation technique used to
minimizing EMI radiation generated by repetitive digital
signals. A clock presents the greatest EMI energy at the center
frequency it is generating. Spread Spectrum distributes this
energy over a specific and controlled frequency bandwidth
therefore causing the average energy at any one point in this
band to decrease in value. This technique is achieved by
modulating the clock away from its resting frequency by a
cert ain perc ent age (wh ich also determi nes the a mount o f EMI
reduction). In this device, Spread Spectrum is enabled by
setting specific register bits in the SMBus control Bytes.
Table 4 is a listing of the modes and percentages of Spread
Spectrum modulation that this device incorporates.
Byte 7: Watchdog Time Stamp Register
Bit @Pup Name Description
70 Reserved
60 Reserved
50 Reserved
40 Reserved
30 Reserved
20 Reserved
10 Reserved
00 Reserved
Byte 8: Dial-a-Frequency Control Register N (all bits are read and write functional)
Bit @Pup Name Description
70 N7, MSB
60 N6
50 N5
40 N4
30 N3
20 N2
10 N3
00 N0, LSB
Byte 9: Dial-a-Frequency Control Register R (all bits are read and write functional)
Bit @Pup Name Description
70 R6 MSB
60 R5
50 R4
40 R3
30 R2
20 R1
10 R0, LSB
0 0 R and N register load gate 0 = gate closed (data is latched), 1 = gate open
(data is loading from SMBus registers into R and N)
Table 3. P Value
S(1:0) P
0 0 32005333
0 1 48008000
1 0 96016000
1 1 64010667
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Special Functions
PCIF and IOAPIC Clock Outputs
The PCIF clock outputs are intended to be used, if required,
for systems IOAPIC clock functionality. ANY two of the PCIF
clock outputs can be used as IOAPIC 33-MHz clock outputs.
They are 3.3V outputs will be divided down via a simple
resi stive volt age d ivide r to me et sp ecific sys tem IOAP IC cloc k
voltage requirements. In the event these clocks are not
required, then these clocks can be used as general PCI clocks
or disabled via the assertion of t he PCI_ST P# pin.
3V66_1/VCH Clock Output
The 3V66_1/VCH pin has a dual functionality that is selectable
via SMBus.
Configured as DRCG (66M), SMBus Byte0, Bit 5 = ‘0’
The default condition for this pin is to power up in a 66M
operation. In 66M operation this output is SSCG capable and
when spreading is turned on, this clock will be modulated.
Configured as VCH (48M), SMBus Byte0, Bit 5 = ‘1’
In this mode, the output is configured as a 48-MHz non-s pread
spectrum output. This output is phase aligned with the other
48M outputs (USB and DOT), to within 1 ns pin-to-pin skew.
The switching of 3V66_1/VCH into VCH mode occurs at
system power on. When the SMBus Bit 5 of Byte 0 is
programmed from a ‘0’ to a ‘1’, the 3V66_1/VCH output may
glitch while transitioning to 48M output mode.
PD# (Power-down) Clarification
The PD# (Powe r-down) pin is used to shut of f ALL clocks pr ior
to shutting off power to the device. PD# is an asynchronous
active LOW input. This signa l is sync hroniz ed intern ally to the
device powering down the clock synthesizer. PD# is an
asynchronous function for powering up the system. When PD#
is low, all clocks are d riven to a LOW value and he ld there a nd
the VCO and PLLs are also pow ered down. All clocks are shut
down in a synchronous manner so has not to cause glitches
while transitioning to the low ‘stopped’ state.
PD#–Assertion
When PD# is sampled LOW by two consecutive rising edges
of the CPUC clock, then on the next HIGH-to-LOW transition
of PCIF, the PCIF clock is stopped LOW. On the next
HIGH-to -LOW trans ition of 66Buff, the 66 Buff c lock is st opped
LOW. From this time, each clock will stop LOW on its next
HIGH-to-LOW transition, except the CPUT clock. The CPU
clocks are held with the CPUT clock pin driven HIGH with a
value of 2 x Iref, and CPUC undriven. After the last clock has
stopped, the rest of the generator will be shut down.
Table 4. Spread Spectr um
SS2 SS1 SS0 Spread Mode Spread%
0 0 0 Dow n +0.00, – 0.25
0 0 1 Dow n +0.00, – 0.50
0 1 0 Dow n +0.00, – 0.75
0 1 1 Dow n +0.00, – 1.00
1 0 0 Center +0.13, –0.13
1 0 1 Center +0.25, –0.25
1 1 0 Center +0.37, –0.37
1 1 1 Center +0.50, –1.50
66Buff
PCIF
PWRDWN#
CPU 133MHz
CPU# 133MHz
3V66
66In
REF 14.318MHz
USB 48MHz
Figure 1. Power-down Assertion Timing Waveforms–Buffered Mode
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PD# Deassertion
The powe r-up lat enc y betw e en PD# risin g t o a valid logic ‘1’
level and the starting of all clocks is less than 3.0 ms.
P CI 33M H z
PWRDWN#
CPUT 133M Hz
C PU C 133M Hz
R EF 14.318M H z
USB 48M Hz
SD R A M 133M H z
DDRT 133M Hz
DDRC 133M Hz
AGP 66MHz
Figure 2. Power-down Assertion Timing Waveforms–Unbuffered Mode
CPU 133MHz
3V66
CPU# 133MHz
RE F 14 .318MHz
USB 48 M Hz
PC IF / APIC
33MHz
66In
66Buff
PWRDWN#
6 6B uff1 / GMC H
400uS max<1.8mS
PCI 33M H z
30uS min
Figure 3. Power-down Deassertion Timing Waveforms
Table 5. PD# Functionalit y
PD# DRCG 66CLK (0:2) PCIF/PCI PCI USB/DOT
1 66M 66Input 66Input/2 66Input/2 48M
0 Low Low Low Low Low
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CPU_STP# Clarification
The CPU_STP# signal is an active LOW input used for
synchronous stopping and starting the CPU output clocks
while the rest of the clock generator continues to function.
CPU_STP# Assertion
When C PU_STP# pin is asserted, all CPUT/C outputs that are
set with the SMBus configuration to be stoppable via assertion
of CPU_STP# will be stopped after being sampled by two
falling CPUT/C clock edges. The final state of the stopped
CPU signals is CPUT = HIGH and CPU0C = LOW . There is no
change to the output drive current values during the stopped
state. The CPUT is driven HIGH with a current value equal to
(Mult 0 ‘select’) x (Iref), and the CPUC signal will not be driven.
Due to external pull-down circuitry CPUC will be LOW during
this stopped state.
CPU_STP# D eas sertio n
The deassertion of the CPU_STP# signal will cause all
CPUT/C outputs that were stopped to resume normal
operation in a synchronous manner. Synchronous manner
meaning that no short or stretched clock pulses will be
produces when the clock resumes. The maximum latency
from the deassertion to active outputs is no more than two
CPUC clock cycles.
CPU_STP#
CPUT
CPUC
CPUT
CPUC
Figure 4. CPU_STP# Assertion Waveforms
CPU_STP#
CPUT
CPUC
CPUT
CPUC
Figure 5. CPU_STP# Deassertion Waveforms
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Three-st ate Control of CPU Clocks Clarification
During CPU_STP# and PD# modes, CPU clock outputs may
be set to driven or undriven (three-state) by setting the corre-
sponding SMBus entry in Bit6 of Byte0 and Bit6 of Byte1.
PCI_STP# Assertion
The PCI_STP# signal is an active LOW input used for
synchronous stopping and starting the PCI outputs while the
rest of the clock generator continues to function. The set-up
time fo r capturing PCI_ST P# going LOW is 10 ns (tsetup). (See
Figure 2.) The PCIF (0:2) clocks will not be af fected by this pin
if their control bits in the SMBus register are set to allow them
to be free running.
PCI_STP# Deassertion
The deas sertion of the PCI_STP# signal will cause all PCI and
stoppable PCIF clocks to resume running in a synchronous
manner within two PCI clock periods after PCI_STP# transi-
tions to a high level.
Note that the PCI STOP func tion is controlled by two inputs.
One is the device PCI_STP# pin number 34 and the other is
SMBus byte 0 bit 3. These two inputs to the function are
logically ANDed. If either the external pin or the internal
SMBus register bit is set low then the stoppable PCI clocks will
be stopped in a logic low state. Reading SMBus Byte 0 Bit 3
will return a 0 value if either of these control bits are set LOW
thereby indicating the devices stoppable PCI clocks are not
running.
Table 6. Cypress Clock Power Management Truth Table
B0b6 B1b6 PD# CPU_STP# Stoppable
CPUT Stoppable
CPUC Non-Stop CPUT Non-Stop CPUC
0 0 1 1 Running Running Running Running
0 0 1 0 Iref x6 Iref x6 Running Running
0 0 0 1 Iref x2 Low Iref x2 Low
0 0 0 0 Iref x2 Low Iref x2 Low
0 1 1 1 Running Running Running Running
0 1 1 0 Hi Z Hi Z Running Running
0101Hi ZHi ZHi Z Hi Z
0100Hi ZHi ZHi Z Hi Z
1 0 1 1 Running Running Running Running
1 0 1 0 Iref x6 Iref x6 Running Running
1001Hi ZHi ZHi Z Hi Z
1000Hi ZHi ZHi Z Hi Z
1 1 1 1 Running Running Running Running
1 1 1 0 Hi Z Hi Z Running Running
1101Hi ZHi ZHi Z Hi Z
1100Hi ZHi ZHi Z Hi Z
PCI_STP#
PCIF 33M
PCI 33M
setup
t
Figure 6. PCI_STP# Assertion Waveforms
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PCI_STP#
PCIF
PCI
setup
t
Figure 7. PCI_STP# Deassertion Waveforms
Figure 8. VTT_PWRGD# Timing Diagram
VID
SEL
VTT_PWRGD#
PWRGD
VD D Clock Ge n
Clock State
Clock Outpu ts
Clock VCO
0.2-0.3mS
Delay
State 0 St a te 2 State 3
Wait for
VTT_PWRGD# Sample Sels
Off
Off
On
On
State 1
Device is not affected ,
VTT_PW RGD# is ignored.
VTT_PWRGD# = Low
Delay
>0.25mS
S1
Power Off
S0
VDDA = 2.0V
Sample
Inputs straps
S2
Normal
Operation
W ait for <1.8 m s
Enable Outputs
S3
VTT_PWRGD# = toggle
VDD3.3= off
Figure 9. Clock Generator Power-up/Run State Program
Table 7. Host Clock (HCSL) Buffer Characteristics
Characteristic Minimum Maximum
Ro 3000 Ohms (recommended) N/A
Ros
Vout N/A 1.2V
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Document #: 38-07509 Rev. *A Page 12 of 20
Iout is selectable depending on implementation. The param-
eters above apply to all configurations. Vout is the voltage at
the pin of the device.
The various output current configurations are shown in the
host swing select functions table. For all configurations, the
deviat ion from the e xpected output c urrent is ± 7% as show n in
the current accuracy table.
USB and DOT 48M Phase Relationship
The 48M_ USB and 48M_DO T clocks are in phas e. It is under-
stood that the difference in edge rate will introduce some in
inherent offset. When 3V66_1/VCH clock is configured for
VCH (48-MHz) operatio n it is also in phase with the USB and
DOT output s . See Figure 10.
66IN to 66B Buffered Prop Delay
The 66IN to 66B(0:2) output delay is shown in Figure 11.
The Tpd is the prop delay from the input pin (66IN) to the
output pins (66B[0:2]). The outputs’ variation of Tpd is
described in the AC parameters section of this data sheet. The
measurement is taken at 1.5V.
66B to PCI Buffered Clock Skew
Figure 12 shows the dif ferenc e (skew) betw een the 3V33(0 :5)
outputs when the 66M clocks are connected to 66IN. This
offset is descr ibed in the Group T iming Relationship and Toler-
ances section of this data sheet. The measurements were
taken at 1.5V.
3V66 to PCI Unbuffered Clock Skew
Figure 13 shows the timing relationship between 3V66(0:5)
and P CI(0:6 ) and PC IF when configur ed to r un in th e unbuf -
fered mode.
Table 8. CPU Clock Current Select Function
Mult0 Board Target Trace/Term Z Reference R, Iref – Vdd (3*Rr) Output Current Voh @ Z
0 50 Ohms Rr = 221 1%, Iref = 5.00 mA Ioh = 4*Iref 1.0V @ 50
1 50 Ohms Rr = 475 1%, Iref = 2.32 mA Ioh = 6*Iref 0.7V @ 50
Table 9. Group Timing Relationship and Tolerances
Description Offset Tolerance Conditions
3V66 to PCI 2.5 ns ±1.0 ns 3V66 Leads PCI (unbuffered mode)
48M_USB to 48M_DOT Skew 0.0 ns ±1.0 ns 0 degrees phase shift
66B to PCI offset 2.5 ns ±1.0 ns 66B leads PCI (buffered mode)
Table 10. Maximum Lumped Capa citive Output Loads
Clock Max Load Unit
PCI Clocks 30 pF
3V66 30 pF
66B 30 pF
48M_USB Clock 20 pF
48M_DOT 10 pF
REF Clock 50 pF
48MUSB
48MDOT
Figure 10. 48M_USB and 48M_DOT Phase Relationship
66IN
66B
Tpd
Figure 11. 66IN to 66B(0:2) Output Delay Figure
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Buffer Characteristics
Current Mode CPU Clock Buffer Characteristics
The current mode output buffer detail and current reference
circuit details are contained in the previous table of this data
sheet. The following parameters are used to specify output
buffer charac teristics:
1. Output impedance of the current mode buffer circuit – Ro
(see Figure 14).
2. Minimum and ma ximum required vo ltage o peration range
of the circuit – Vop (see Figure 14).
3. Series resist ance in the buffer circuit – Ros (see Figure 14).
4. Current accura cy at given configuration into nom inal test
load for given configuration.
66B
PCI
PCIF
1.5-
3.5ns
Figure 12 . Buffer Mode – 33V66(0:1); 66BUF(0 :2) Phase R elationship
PCI
PCIF
Tpci
3V66
Figure 13. Unbuffered Mode – 3V66(0:5) to PCI (0:6) and PCIF(0:2) Phase Relationship
1.2V0V
Iout
Iout
Ros
Ro
VDD3 (3.3V +/- 5%)
Vout = 1.2V max Vout
Slope ~ 1/R
0
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Absolute Maximum Conditions
Parameter Description Condition Min. Max. Unit
VDD Core Supply Voltage –0.5 4.6 V
VDD_A Analog Supply Voltage –0.5 4.6 V
VIN Input Voltage Relative to V SS –0.5 VDD + 0.5 VDC
TSTemperature, Storage Non-functional –65 150 °C
TATemperature, Operating A m bien t Fun ctional 0 85 °C
TJTemperature, Junction Functional 150 °C
ØJC Dissipation, Junction to Case Mil-Spec 883E Method 1012.1 45 °C/W
ØJA Dissipation, Junction to Ambient JEDEC (JESD 51) 15 °C/W
ESDHBM ESD Protection (Human Body Model) MIL -STD-88 3, Method 3015 2000 V
Ul-94 Flammability Rating V–0 @1/8 in. 10 ppm
MSL Moisture Sensitivity Level 1
DC Parameters (VDD = VDDA = 3.3V ±5%)
Parameter Description Conditions Min. Typ. Max. Unit
Idd3.3V Dynamic Supply Current All frequencies at maximum values[3] 280 mA
Ipd3.3V Power-down Supply Current PD# Asserted Note 4 mA
Cin Input Pin Capacitance 5pF
Cout Output Pin Capacitance 6pF
Lpin Pin Inductance 7nH
Cxtal Crystal Pin Capa citance Measured from the Xin or Xout Pin to Ground. 30 36 42 pF
AC Parameters (VDD = VDDA = 3.3V ±5%)
Parameter Description 66 MHz 100 MHz 133 MHz 200 MHz Unit NotesMin. Max. Min. Max. Min. Max. Min. Max.
Crystal
Tdc Xin Duty Cycle 47.5 52.5 47.5 52.5 47.5 52.5 47.5 52.5 % 5, 6, 7
Tperiod Xin Period 69.84 71.0 69.84 71.0 69.84 71.0 69.84 71.0 ns 5, 8, 9, 6
Vhigh Xin High Voltage 0.7Vdd Vdd 0.7Vdd Vdd 0.7Vdd Vdd 0.7Vdd Vdd V
Vlow Xin Low Voltage 0 0.3Vdd 0 0.3Vdd 0 0.3Vdd 0 0.3Vdd V
Tr/Tf Xin Rise and Fall
Times 10.0 10.0 10.0 10.0 ns 10
Tccj Xin Cycle to Cycle
Jitter 500 500 500 500 ps 8, 11, 6
CPU at 0.7V Timing
Tdc CPUT and CPUC
Duty Cycle 45 55 45 55 4 5 55 45 55 % 11, 12, 13
Tperiod CPUT and CPUC
Period 14.85 15.3 9.85 10.2 7.35 7.65 4.85 5.1 ns 11, 12, 13
Tskew Any CPU to CPU
Clock Skew 100 100 100 100 ps 8, 11, 12
Notes:
3. All outputs loaded as per maximum capacitive load table.
4. Absolute value = ((Programmed CPU Iref) x (2)) + 10 mA.
5. This parameter is measured as an average over 1-µs duration, with a crystal center frequency of 14.31818 MHz
6. When Xin is driven from an external clock source.
7. This is required fo r the duty cy cle on the REF clock o ut to be as specified . The de vice will operate re liably with in put duty cycles up to 30/70 but the REF clock
duty cycle will not be within data sheet specifications.
8. All outputs loaded as perTable 10 below.
9. Probes are placed on the pins and measurements are acquired at 1.5V for 3.3V sign als (s ee test and measurement se t-up section of this data sheet).
10. Measured between 0.2Vdd and 0.7Vdd.
11. This meas uremen t is appl i cabl e with Spread ON or S pread OFF.
12. Measured at crossing point (Vx) or where subtraction of CLK-CLK# crosses 0 volts Measured from Vol = 0.175V to Voh = 0.525V.
13. Test load is Rt a = 33.2 ohms, Rd = 49.9 ohms.
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Tccj CPU Cycle to
Cycle Jitter 150 150 150 150 ps 11, 12, 13
Tr/Tf CPUT and CPUC
Rise and Fall
Times
175 700 175 7 00 175 700 175 700 ps 11, 14, 16
Rise/Fall Matching 20% 20% 20% 20% 14, 1 5, 13
DeltaTr Rise Time
Variation 125 125 125 125 ps 14, 13
DeltaTf Fall Time
Variation 125 125 125 125 ps 14, 13
Vcross Crossing P oin t
Voltage at 0.7V
Swing
280 430 280 430 280 430 280 430 mV 11, 13
CPU at 1.0V Timing
Tdc CPUT and CPUC
Duty Cycle 45 55 45 55 45 55 45 55 % 11, 12
Tperiod CPUT and CPUC
Period 14.85 15.3 9.85 10.2 7.35 7.65 4.85 5.1 nS 11, 12
Tskew Any CPU to Any
CPU Clock Skew 100 100 100 100 pS 8, 11, 12
Tccj CPU Cycle to
Cycle Jitter 150 150 150 150 pS 8, 12
Differential
Tr/Tf CPUT and CPUC
Rise and Fall Times 175 467 175 467 175 467 175 467 ps 11, 16
SE-
DeltaSlew Abs olute Sing le-
ended Rise/Fall
Waveform
Symmetry
325 325 325 325 ps 17, 18
Vcross Cross Point at
1.0V swing 510 760 510 760 510 760 510 760 mV 18
3V66
Tdc 3V66 Duty Cycle4555455545554555%8, 9
Tperiod 3V66 Period 15.0 15.3 15.0 15.3 15.0 15.3 15.0 15.3 ns 5, 8, 9
Thigh 3V66 High Time 4.95 4.95 4.95 4.95 ns 19
Tlow 3V66 Low Time 4.55 4.55 4.55 4.55 ns 20
Tr / Tf 3V66 Rise and
Fall Times 0.5 2.0 0.5 2.0 0.5 2.0 0.5 2.0 ns 21
Tskew
Unbuffered 3V66 to 3V66
Clock Skew 500 500 500 500 ps 8, 9
Tskew
Buffered 3V66 to 3V66
Clock Skew 250 250 250 250 ps 8, 9
Tccj DRCG Cycle to
Cycle Jitter 250 250 250 250 ps 8, 9
14. Measured from Vol = 0.175V to Voh = 0.525V.
15. Determined as a fraction of 2*(Trise – Tfall)/ (Trise + Tfall).
16. Measurement taken from differential waveform, from –0.35V to +0.35V.
17. Measurements taken from common mode waveforms, measure rise/fall time from 0.41 to 0.86V. Rise/fall time matching is defined as “the instantaneous
difference between maximum clk rise (fall) and minimum clk# fall (rise) time or minimum clk rise (fall) and maximum clk# fall (rise) time”. This parameter is
designed form waveform symmetry.
18. Measured in absolute voltage, i.e. single-ended measurement.
19. THIGH is measured at 2.4V for non host outputs.
20. TLOW is measured at 0.4V for all outputs.
21. Probes are placed on the pins, and measurements are acquired between 0.4V and 2.4V for 3.3V signals (see test and measurement set-up section of this data
sheet).
AC Parameters (VDD = VDDA = 3.3V ±5%) (continued)
Parameter Description 66 MHz 100 MHz 133 MHz 200 MHz Unit NotesMin. Max. Min. Max. Min. Max. Min. Max.
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66B
Tdc 66B(0:2) Duty Cycle4555455545554555% 8, 9
Tr / Tf 66B(0:2) Rise and
Fall Times 0.5 2 .0 0.5 2.0 0.5 2. 0 0.5 2.0 ns 8, 21
Tskew Any 66B to Any
66B Skew 175 175 175 175 ps 8, 9
Tpd 66IN to 66B(0:2)
Propagation Delay 2.5 4.5 2.5 4.5 2.5 4.5 2.5 4.5 ns 8, 9
Tccj 66B(0:2) Cycle to
Cycle Jitter 100 100 100 100 ps 8, 9, 22
PCI
Tdc PCIF(0:2) PCI
(0:6) Duty Cycle 45 55 45 55 45 55 45 55 % 8, 9
Tperiod PCIF(0:2) PCI
(0:6) period 30.0 30.0 30.0 30 nS 5, 8, 9
Thigh PCIF(0:2) PCI
(0:6) high time 12.0 12.0 12.0 12.0 nS 19
Tlow PCIF(0:2) PCI
(0:6) low time 12.0 12.0 12.0 12.0 nS 20
Tr/Tf PCIF(0:2) PCI
(0:6) rise and fall
times
0.5 2.0 0.5 2.0 0.5 2.0 0.5 2.0 nS 21
Tskew Any PCI clock to
Any PCI clock
Skew
500 500 500 500 pS 8, 9
Tccj PCIF(0:2) PCI
(0:6) Cycle to
Cycle Jitter
250 250 250 250 ps 8, 9
48M_USB
Tdc 48M_USB Duty
Cycle 45 55 45 55 45 55 45 55 % 8, 9
Tperiod 48M_USB Period 20.8299 20.8333 20.8299 20.8333 20.8299 20.8333 20.8299 20.8333 ns 8, 9
Tr/Tf 48M_USB Rise
and Fall Times 1.0 2.0 1.0 2.0 1.0 2.0 1.0 2.10 ns 8, 21
Tccj 48M_USB Cycle
to Cycle Jitter 350 350 350 350 ps 5, 8, 9
48M_DOT
Tdc 48M_DOT Duty
Cycle 45 55 45 55 45 55 45 55 % 8, 9
Tperio d 48M_DOT Period 20.837 20.837 20.837 20.837 ns 8, 9
T r/Tf 48M_DOT Rise
and Fall Times 0. 5 1.0 0.5 1.0 0.5 1.0 0.5 1. 0 ns 8, 9
Tccj 48M_DOT Cycle
to Cycle Jitter 350 350 350 350 ps 8, 9
REF
Tdc REF Duty Cycle4555455545554555%8, 9
Tperiod REF Period 69.84 71.0 6 9.84 71.0 69.84 71.0 69.84 71.0 ns 8, 9
Note:
22. This figure is additive to any jitter already present when the 66IN pin is being used as an input. Otherwise a 500-ps jitter figure is specified.
AC Parameters (VDD = VDDA = 3.3V ±5%) (continued)
Parameter Description 66 MHz 100 MHz 133 MHz 200 MHz Unit NotesMin. Max. Min. Max. Min. Max. Min. Max.
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Document #: 38-07509 Rev. *A Page 17 of 20
Test and Measurement Set-up
For Differential CPU Output Signals
The following diagram shows lumped test load configurations
for the differential Host Clock Outputs.
Notes:
23. CPU_STP# and PCI _STP# se tup time with respect to any PCIF clock to guarantee that the ef fected clock will st op or sta rt at the next PCIF clock’s rising edge.
24. When Crystal meets minimum 40-ohm device series resistance specification.
Tr / Tf REF Rise and Fall
Times 1. 0 4 .0 1.0 4.0 1.0 4.0 1.0 4.0 ns 8, 21
Tccj REF Cycle to
Cycle Jitter 1000 1000 1000 1000 ps 8, 9
Tpzl/Tpzh Output Enable
Delay (all outpu ts) 1.0 10.0 1.0 10.0 1.0 10.0 1.0 10.0 ns 6
Tplz/Tpzh Output disable
delay (all outputs) 1.0 10.0 1.0 10.0 1.0 10.0 1.0 10.0 ns 6
Tstable All Clock Stabili-
zation from
Power-up
3333ms6
Tss Stopclock Set-up
Time 10.0 10.0 10.0 10.0 ns 23
Tsh Stopclock Hold
Time 0000ns23
Tsu Oscillator S tart-up
Time 1.2 1.2 1.2 1.2 ms 24
AC Parameters (VDD = VDDA = 3.3V ±5%) (continued)
Parameter Description 66 MHz 100 MHz 133 MHz 200 MHz Unit NotesMin. Max. Min. Max. Min. Max. Min. Max.
M easurem ent Poin t
2pF
CPUT
MULTSEL
TPCB
TPCB
CPUC
220Ω
63.4Ω 63.4Ω
475Ω
33.2Ω
33.2Ω Measu rem en t Point
2pF
Figure 15. 1.0V Test Load Termination
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Document #: 38-07509 Rev. *A Page 18 of 20
For Single-Ended Output Signals
CPUT
MULTSEL
TPCB
TPCB
CPUC
33Ω
33Ω M easurement Point
49.9Ω
49.9Ω 2pF
Me asurement Point
2pF
221Ω
VDD
Figure 16. 0.7V Test Load Termination
Ordering Information
Part Number Package Type Product Flow
CY2 8346ZC-2 56-pin TSSOP–Tube Commercial, 0° to 70°C
CY2 8346ZC-2T 56-pin TSSOP –Tape and Reel Commerc i al, 0° to 70°C
CY2 8346ZI-2 56-pin TSSOP–Tube Industrial, 0° to 85°C
CY2 8346ZI-2T 56-pin TSSOP–Tape and Reel Industrial, 0° to 85°C
2
.4V
0
.4V
3.3V
0V
Tr Tf
1
.5V
3.3V signals
tDC
Probe
Output under Test
Load Cap
--
Figure 17.
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Document #: 38-0750 9 Rev. *A Page 19 of 20
© Cypress Semiconductor Corporation, 2003. The information contained herein is subject to change without notice. Cypress Semiconductor Corporation assumes no responsibility for the use
of any ci rcuitry other th an circuitry embod ied in a Cypr ess Semiconductor pr oduct. Nor does it convey or imply any licen se under p atent or other rights. C ypress Semicond uctor does not authorize
its products for use as critical components in life-support systems where a malfunction or failure may reasonably be expected to result in significant injury to the user. The inclusion of Cypress
Semiconductor products in life-support systems application implies that the manufacturer assumes all risk of such use and in doing so indemnifies Cypress Semiconductor against all charges.
Package Drawings and Dimensions
Intel is a regi ste r ed trade ma rk of Intel Corporation. Dial -a-Fre que ncy i s a re gis tere d tra dem ark , an d Dia l-a-d B is a trad em ark, of
Cypress Semiconductor. All product and company names mentioned in this document are the trademarks of their respective
holders.
51-85060-*B
56-lead Thin Shrunk Small Outline Package, Type II (6 mm x 14 mm) Z56
CY28346
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Document #: 38-07509 Rev. *A Page 20 of 20
Document History Page
Document Title: CY28346-2 Clock Synthesizer with Differential CPU Outputs
Document Number: 38-07509
REV. ECN NO. Issue
Date Orig. of
Change Description of Change
** 122429 12/11/02 RGL New Data Sheet
*A 127147 06/10/03 RGL Corrected the value of TSU parameter in the AC parameters table from x to 1.2
Removed “Preliminary” (it is a final data sheet)