ICS ICS94225

ICS94225
Integrated
Circuit
Systems, Inc.
AMD-K7TM System Clock Chip
Output Features:
•
3 differential pair open drain CPU clocks (1.5V
external
pull-up; up to 150MHz achieviable through I2C)
•
2 - AGPCLK @ 3.3V
•
8 - PCI @3.3V, including 1 free running
•
1 - 48MHz @ 3.3V
•
1 - 24/48MHz @ 3.3V
•
2- REF @3.3V, 14.318MHz.
Features:
•
Programmable ouput frequency
•
Programmable ouput rise/fall time
•
Programmable group skew
•
Real time system reset output
•
Spread spectrum for EMI control typically
by 7dB to 8dB,
with programmable spread percentage
•
Watchdog timer technology to reset system
if over-clocking causes malfunction
•
Uses external 14.318MHz crystal
Block Diagram
48MHz
24_48MHz
/2
XTAL
OSC
PLL1
Spread
Spectrum
REF (1:0)
CPU
DIVDER
Stop
3
3
SDRAM
DIVDER
CPUCLKT (2:0)
CPUCLKC (2:0)
SDRAM_OUT
SEL24_48#
SDATA
Control
SCLK
PD#
PCI_STOP#
CPU_STOP#
SPREAD#
0445B—08/01/03
PCI
DIVDER
Stop
7
AGP
DIVDER
Config.
Reg.
VDDREF
GNDSD
SDRAM_OUT
VDDSD
RESERVED
CPUCLKC2
CPUCLKT2
GNDCPU
CPUCLKC1
CPUCLKT1
GND
CPUCLKC0
CPUCLKT0
RESET#
VDD
GND
PCI_STOP#
CPU_STOP#
PD#
SPREAD#
FS2*
SDATA
SCLK
GND48
48-Pin 300mil SSOP
* Internal 120K pullup resistor on indicated inputs
** Internal 240K pullup resistor on indicated inputs
PCICLK (6:0)
FS2
FS1
FS0
0
0
0
0
1
1
1
1
0
0
1
1
0
0
1
1
0
1
0
1
0
1
0
1
CPU,
SDRAM
133.33
95
100.99
115
100.7
103
105
110
PCICLK_F
Logic
FS (2:0)
48
47
46
45
44
43
42
41
40
39
38
37
36
35
34
33
32
31
30
29
28
27
26
25
Functionality
PLL2
X1
X2
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
**FS0/REF0
**FS1/REF1
GNDREF
X1
X2
GNDPCI
PCICLK_F
PCICLK0
VDDPCI
PCICLK1
PCICLK2
GNDPCI
PCICLK3
PCICLK4
VDDPCI
PCICLK5
PCICLK6
VDDAGP
AGP0
AGP1
GNDAGP
VDD48
48MHz
SEL24_48#/24-48MHz
ICS94225
Pin Configuration
Recommended Application:
AMD 750/760 style chipset
2
AGP (1:0)
Power Groups
VDD48, GND48 = 48MHz, PLL2
VDDREF, GNDREF= REF, X1, X2
VDD, GND = PLL Core
PCI
AGP
33.33
31.67
33.66
38.33
33.57
34.33
35.00
36.67
66.67
63.33
67.33
76.67
67.13
68.67
70.00
73.33
ICS94225
General Description
The ICS94225 is a main clock synthesizer chip for AMD-K7 based systems with AMD 750/760 style chipsets. This
provides all clocks required for such a system.
The ICS94225 belongs to ICS new generation of programmable system clock generators. It employs serial
programming I2C interface as a vehicle for changing output functions, changing output frequency, configuring output
strength, configuring output to output skew, changing spread spectrum amount, changing group divider ratio and dis/
enabling individual clocks. This device also has ICS propriety 'Watchdog Timer' technology which will reset the
frequency to a safe setting if the system become unstable from over clocking.
Pin Descriptions
PIN NUMBER
PIN NAME
FS (1:0)
REF (1:0)
TYPE
IN
OUT
DESCRIPTION
Frequency Select pins, has pull-up to VDD
14.318MHz clock output
3, 6, 21, 25,
33, 38, 41, 47
GND
PWR
Ground
4
X1
IN
5
X2
OUT
7
PCICLK_F
OUT
PCICLK (6:0)
OUT
PCI clock outputs. TTL compatible 3.3V
VDDPCI
VDDAGP
PWR
PWR
Power for PCICLK outputs, nominally 3.3V
Power for AGP outputs, nominally 3.3V
AGP outputs defined as 2X PCI. These may not be
stopped.
Isolated power for core, nominally 3.3V
Power for 48MHz and 24MHz outputs nominally 3.3V
48MHz output
Selects 24 or 48MHz output for pin 24
Low = 48MHz High = 24MHz
Fixed clock out selectable through SEL24-48#
Clock pin of I2C circuitr y 5V tolerant
Data pin for I2C circuitr y 5V tolerant
Frequency Select pin, has pull-up to VDD
Enables Spread Spectrum feature when LOW. Down
Spread 0.5% modulation frequency =50KHz
Powers down chip, active low. Internal PLL & all outputs
are disabled.
Halts CPUCLKs. CPUCLKT is driven LOW wheras
CPUCLKC is driven HIGH when this pin is asser ted
(Active LOW).
Halts PCI Bus at logic "0" level when driven low.
PCICLK_F is not affected by this pin
2,1
17, 16, 14, 13, 11, 10,
8
9, 15
18
20, 19
AGP (1:0)
OUT
34
22
23
VDD
VDD48
48MHz
PWR
PWR
OUT
SEL24-48#
IN
26
27
28
24-48MHz
SCLK
SDATA
FS2
OUT
IN
I/O
IN
29
SPREAD#
IN
30
PD#
IN
31
CPU_STOP#
IN
32
PCI_STOP#
IN
35
RESET#
OUT
46
44
SDRAM_OUT
RESERVED
OUT
N/C
42, 39, 36
CPUCLKT (2:0)
OUT
43, 40, 37
CPUCLKC (2:0)
OUT
45
48
VDDSD
VDDREF
PWR
PWR
24
XTAL_IN 14.318MHz Cr ystal input, has internal 33pF
load cap and feed back resistor from X2
XTAL_OUT Cr ystal output, has internal load cap 33pF
Free Running PCI output. Not affected by the
PCI_STOP# input.
Real time system reset signal for watchdog tmer
timeout. This signal is active low.
Reference clock for SDRAM zero delay buffer
Future CPU power rail
"True" clocks of differential pair CPU outputs. These open
drain outputs need an external 1.5V pull-up.
"Complementar y" clocks of differental pair CPU output.
These open drain outputs need an external 1.5V pull_up.
Power for SDRAM_OUT pin. Norminally 3.3V
Power for REF, X1, X2, nominally 3.3V
0445B—08/01/03
2
ICS94225
Byte 1: Reserved Active/Inactive Register
(1= enable, 0 = disable)
BIT
PIN#
PWD
Bit 7
-
1
Bit 6
-
1
Byte 2: Reserved, Active/Inactive Register
(1= enable, 0 = disable)
DESCRIPTION
BIT
PIN#
PWD
DESCRIPTION
(Reserved)
Bit 7
-
1
(Reserved)
(Reserved)
Bit 6
-
1
(Reserved)
Bit 5
-
1
(Reserved)
Bit 5
-
1
(Reserved)
Bit 4
-
1
(Reserved)
Bit 4
-
1
(Reserved)
-
1
(Reserved)
Bit 3
-
1
(Reserved)
Bit 3
Bit 2
-
1
(Reserved)
Bit 2
-
1
(Reserved)
Bit 1
-
1
(Reserved)
Bit 1
-
1
(Reserved)
Bit 0
-
1
(Reserved)
Bit 0
-
1
(Reserved)
Byte 3: Reserved Active/Inactive Register
(1= enable, 0 = disable)
Byte 4: Clock Control Register
(1= enable, 0 = disable)
BIT
PIN#
PWD
DESCRIPTION
Bit 7
-
1
(Reserved)
7
Bit 6
-
1
(Reserved)
Bit 5
-
1
(Reserved)
BIT
PIN# PWD
DESCRIPTION
1
1
REF0
6
23
1
24MHz/48MHz
5
22
1
USB0
Bit 4
-
1
(Reserved)
4
20
1
AGP1
Bit 3
-
1
(Reserved)
3
19
1
AGP0
Bit 2
-
1
(Reserved)
2
42, 43
1
CPUCLKC/T2
Bit 1
-
1
(Reserved)
1
39, 40
1
CPUCLKC/T1
Bit 0
-
1
(Reserved)
0
36, 37
1
CPUCLKC/T0
Byte 5: PCI Clock Control Register
(1= enable, 0 = disable)
BIT
PIN# PWD
DESCRIPTION
7
2
1
REF1
6
17
1
PCICLK6
5
16
1
PCICLK5
4
14
1
PCICLK4
3
13
1
PCICLK3
2
11
1
PCICLK2
1
10
1
PCICLK1
0
8
1
PCICLK0
Notes:
1. Inactive means outputs are held LOW and are disabled
from switching.
2. Latched Frequency Selects (FS#) will be inverted logic
load of the input frequency select pin conditions.
0445B—08/01/03
3
ICS94225
Byte 6: SDRAM Clock & Generator Mode Control Register
Bit
7
6:2
Description
Spread Spectrum enable (+/- 0.25% center spread) 0=OFF 1=ON
Bit 3
Bit 2
FS2
Bit 6
FS1
Bit 5
FS0
Bit 4
CPU,
SDRAM
PCI
AGP
0
0
0
0
0
133.33
33.33
66.67
0
0
0
0
1
95
31.67
63.33
0
0
0
1
0
100.99
33.66
67.33
0
0
0
1
1
115
38.33
76.67
0
0
1
0
0
100.7
33.57
67.13
0
0
1
0
1
103
34.33
68.67
0
0
1
1
0
105
35.00
70.00
0
0
1
1
1
110
36.67
73.33
0
1
0
0
0
102
34.00
68.00
0
1
0
0
1
104
34.67
69.33
0
1
0
1
0
106
35.33
70.67
0
1
0
1
1
107
35.67
71.33
0
1
1
0
0
108
36.00
72.00
0
1
1
0
1
109
36.33
72.67
0
1
1
1
0
90
30.00
60.00
0
1
1
1
1
111
37.00
74.00
1
0
0
0
0
112
37.33
74.67
1
0
0
0
1
113
37.67
75.33
1
0
0
1
0
114
38.00
76.00
1
0
0
1
1
116
38.67
77.33
1
0
1
0
0
117
39.00
78.00
1
0
1
0
1
118
39.33
78.67
1
0
1
1
0
119
39.67
79.33
1
0
1
1
1
120
30.00
60.00
1
1
0
0
0
142
35.50
71.00
1
1
0
0
1
144
36.00
72.00
1
1
0
1
0
146
36.50
73.00
1
1
0
1
1
138
34.50
69.00
1
1
1
0
0
136
34.00
68.00
1
1
1
0
1
135
33.75
67.50
1
1
1
1
1
1
1
1
0
1
140
150
35.00
37.50
70.00
75.00
PWD
0
0010
Note1
1
0 - Frequency is selected by hardware select, latched input;
Spread controlled by pin 29
1 - Frequency is selected by Bit (6:2); Spread controlled by Bit
0
0
0 - SDRAM_OUT Disable
1 - SDRAM_OUT Enable
1
Notes:
1. Default at power-up will be latched logic inputs to define frequency, as displayed by Bit 1.
2. PWD = Power-Up Default
0445B—08/01/03
4
ICS94225
Byte 7: Vendor ID and Revision ID Register
Bit
Bit 7
Bit 6
Bit 5
Bit 4
Bit 3
Bit 2
Bit 1
Bit 0
PWD
0
0
1
X
X
X
X
X
Byte 8: Byte Count and Read Back Register
Bit
Bit 7
Bit 6
Bit 5
Bit 4
Bit 3
Bit 2
Bit 1
Bit 0
Description
Vendor ID
Vendor ID
Vendor ID
Revision ID
Revision ID
Revision ID
Revision ID
Revision ID
PWD
0
0
0
0
0
0
0
0
Description
Reserved
Reserved
Reserved
Reserved
Reserved
Reserved
Reserved
Reserved
Byte 10: VCO Control Selection Bit &
Watchdog Timer Control Register
Byte 9: Watchdog Timer Count Register
Bit
Bit 7
Bit 6
Bit 5
Bit 4
Bit 3
Bit 2
Bit 1
Bit 0
PWD
0
0
0
0
1
0
0
0
Bit
Bit 7
Bit 6
Bit 5
Bit 4
Bit 3
Bit 2
Bit 1
Bit 0
Description
The decimal representation of these
8 bits correspond to 290ms or 1ms
the watchdog timer will wait before
it goes to alarm mode and reset the
frequency to the safe setting. Default
at power up is 290ms.
PWD
0
0
0
1
0
0
0
0
Description
0=Hw/B0 freq / 1=B11 & 12 freq
WD Enable 0=disable / 1=enable
WD Status 0=normal / 1=alarm
WD Safe Frequency, Byte 0 bit 2
WD Safe Frequency, FS3
WD Safe Frequency, FS2
WD Safe Frequency, FS1
WD Safe Frequency, FS0
Note: FS values in bit [0:4] will correspond to Byte 0 FS
values. Default safe frequency is same as 00000
entry in byte0.
Byte 12: VCO Frequency Control Register
Byte 11: VCO Frequency Control Register
Bit
Bit 7
Bit 6
Bit 5
Bit 4
Bit 3
Bit 2
Bit 1
Bit 0
PWD
X
X
X
X
X
X
X
X
Bit
Bit 7
Bit 6
Bit 5
Bit 4
Bit 3
Bit 2
Bit 1
Bit 0
Description
VCO Divider Bit0
REF Divider Bit6
REF Divider Bit5
REF Divider Bit4
REF Divider Bit3
REF Divider Bit2
REF Divider Bit1
REF Divider Bit0
PWD
X
X
X
X
X
X
X
X
Description
VCO Divider Bit8
VCO Divider Bit7
VCO Divider Bit6
VCO Divider Bit5
VCO Divider Bit4
VCO Divider Bit3
VCO Divider Bit2
VCO Divider Bit1
Note: The decimal representation of these 9 bits (Byte
12 bit [7:0] & Byte 11 bit [7] ) + 8 is equal to the VCO
divider value. For example if VCO divider value of 36
is desired, user need to program 36 - 8 = 28, namely, 0,
00011100 into byte 12 bit & byte 11 bit 7.
Note: The decimal representation of these 7 bits (Byte 11
[6:0]) + 2 is equal to the REF divider value .
Notes:
1. PWD = Power on Default
0445B—08/01/03
5
ICS94225
Byte 13: Spread Sectrum Control Register
Bit
Bit 7
Bit 6
Bit 5
Bit 4
Bit 3
Bit 2
Bit 1
Bit 0
PWD
X
X
X
X
X
X
X
X
Byte 14:
Description
Spread Spectrum Bit7
Spread Spectrum Bit6
Spread Spectrum Bit5
Spread Spectrum Bit4
Spread Spectrum Bit3
Spread Spectrum Bit2
Spread Spectrum Bit1
Spread Spectrum Bit0
Bit
Bit 7
Bit 6
Bit 5
Bit 4
Bit 3
Bit 2
Bit 1
Bit 0
Spread Sectrum Control Register
PWD
X
X
X
X
X
X
X
X
Description
Reserved
Reserved
Reserved
Spread Spectrum Bit12
Spread Spectrum Bit11
Spread Spectrum Bit10
Spread Spectrum Bi 9
Spread Spectrum Bit8
Note: Please utilize software utility provided by ICS
Application Engineering to configure spread
spectrum. Incorrect spread percentage may cause
system failure.
Note: Please utilize software utility provided by ICS
Application Engineering to configure spread
spectrum. Incorrect spread percentage may cause
system failure.
Byte 15: Output Skew Control
Byte 16: Output Skew Control
Bit
Bit 7
Bit 6
Bit 5
Bit 4
Bit 3
Bit 2
Bit 1
Bit 0
PWD
Description
X
X
CPUCLKC2/T2 Skew Control
X
X
X
X
PCICLK_F Skew Control
X
X
Bit
Bit 7
Bit 6
Bit 5
Bit 4
Bit 3
Bit 2
Bit 1
Bit 0
Byte 17: Output Rise/Fall Time Select Register
Bit
Bit 7
Bit 6
Bit 5
Bit 4
Bit 3
Bit 2
Bit 1
Bit 0
PWD
X
X
X
X
X
X
X
X
PWD
Description
X
X
PCICLK (6:0) Skew Control
X
X
X
X
AGP (3:0) Skew Control
X
X
Byte 18: Output Rise/Fall Time Select Register
Description
Bit
Bit 7
Bit 6
Bit 5
Bit 4
Bit 3
Bit 2
Bit 1
Bit 0
CPUCLKT0
CPUCLKC0
CPUCLKT1
CPUCLKC1
AGP (2:0) Slew Rate Control
3V66 (1:0) Slew Rate Control
PWD
X
X
X
X
X
X
X
X
Description
PCI (3:0): Slew Rate Control
PCI (6:4): Slew Rate Control
48MHz: Slew Rate Control
24MHz: Slew Rate Control
Notes:
1. PWD = Power on Default
2. The power on default for byte 13-20 depends on the harware (latch inputs FS[0:4]) or I2C (Byte 0 bit [1:7]) setting.
Be sure to read back and re-write the values of these 8 registers when VCO frequency change is desired for the first
pass.
3. If Byte 8 bit 7 is driven to "1" meaning programming is intended, Byte 21-24 will lose their default power up value.
0445B—08/01/03
6
ICS94225
Byte 19: Reserved Register
Bit
Bit 7
Bit 6
Bit 5
Bit 4
Bit 3
Bit 2
Bit 1
Bit 0
PWD
X
X
X
X
X
X
X
X
Byte 20: Reserved Register
Description
Bit
Bit 7
Bit 6
Bit 5
Bit 4
Bit 3
Bit 2
Bit 1
Bit 0
Reserved
Reserved
Reserved
Reserved
Reserved
Reserved
Reserved
Reserved
PWD
X
X
X
X
X
X
X
X
Description
Reserved
Reserved
Reserved
Reserved
Reserved
Reserved
Reserved
Reserved
Note: Byte 19 and 20 are reserved registers, these
VCO Programming Constrains
VCO Frequency ...................... 150MHz to 500MHz
VCO Divider Range ................ 8 to 519
REF Divider Range ................. 2 to 129
Phase Detector Stability .......... 0.3536 to 1.4142
Useful Formula
VCO Frequency = 14.31818 x VCO/REF divider value
Phase Detector Stabiliy = 14.038 x (VCO divider value)-0.5
are unused registers writing to these registers
will not affect device performance or
functinality.
To program the VCO frequency for over-clocking.
0. Before trying to program our clock manually, consider using ICS provided software utilities for easy
programming.
1. Select the frequency you want to over-clock from with the desire gear ratio (i.e. CPU:SDRAM:3V66:PCI ratio) by
writing to byte 0, or using initial hardware power up frequency.
2. Write 0001, 1001 (19H) to byte 8 for readback of 21 bytes (byte 0-20).
3. Read back byte 11-20 and copy values in these registers.
4. Re-initialize the write sequence.
5. Write a '1' to byte 9 bit 7 and write to byte 11 & 12 with the desired VCO & REF divider values.
6. Write to byte 13 to 20 with the values you copy from step 3. This maintains the output spread, skew and slew
rate.
7. The above procedure is only needed when changing the VCO for the 1st pass. If VCO frequency needed to be
changed again, user only needs to write to byte 11 and 12 unless the system is to reboot.
Note:
1. User needs to ensure step 3 & 7 is carried out. Systems with wrong spread percentage and/or group to group skew
relation programmed into bytes 13-16 could be unstable. Step 3 & 7 assure the correct spread and skew relationship.
2. If VCO, REF divider values or phase detector stability are out of range, the device may fail to function correctly.
3. Follow min and max VCO frequency range provided. Internal PLL could be unstable if VCO frequency is too fast or
too slow. Use 14.31818MHz x VCO/REF divider values to calculate the VCO frequency (MHz).
4. ICS recommends users, to utilize the software utility provided by ICS Application Engineering to program the VCO
frequency.
5. Spread percent needs to be calculated based on VCO frequency, spread modulation frequency and spreadamount
desired. See Application note for software support.
0445B—08/01/03
7
ICS94225
Absolute Maximum Ratings
Supply Voltage . . . . . . . . . . . . . . . . . . . . . . . . . 5.5 V
Logic Inputs . . . . . . . . . . . . . . . . . . . . . . . . . . . GND –0.5 V to VDD +0.5 V
Ambient Operating Temperature . . . . . . . . . . 0°C to +70°C
Storage Temperature . . . . . . . . . . . . . . . . . . . . –65°C to +150°C
Stresses above those listed under Absolute Maximum Ratings may cause permanent damage to the device. These
ratings are stress specifications only and functional operation of the device at these or any other conditions above those
listed in the operational sections of the specifications is not implied. Exposure to absolute maximum rating conditions
for extended periods may affect product reliability.
Electrical Characteristics - Input/Supply/Common Output Parameters
TA = 0 - 70°C; Supply Volt age VDD = 3.3 V +/-5% (unless otherwise stated)
PARAMETER
SYMBOL
CONDITIONS
VIH
Input High Voltage
Input Low Voltage
VIL
Input High Current
IIH
Input Low Current
IIL1
Input Low Current
Supply Current
Power Down
Input frequency
1
Input Capacitance
MIN
2
TYP
VSS - 0.3
VIN = VDD
VIN =0 V; Inputs with no pull-up
MAX
VDD + 0.3
UNITS
V
0.8
V
5
A
-5
IDD3.3OP66
resistors
VIN =0 V; Inputs with pull-up
resistors
CL =0 pF; Select@ 66MHz
IDD3.3OP100
CL =0 pF; Select@ 100MHz
91
180
mA
IDD3.3OP133
CL =0 pF; Select@ 133MHz
PD
Fi
VDD = 3.3 V
104
3.25
14.318
5
16
mA
MHz
CIN
Logic Inputs
5
pF
CIN
Logic Inputs
5
pF
CINX
X1 & X2 pins
45
pF
3
ms
4
ns
IIL2
TSTAB
mA
-200
87
12
27
From VDD= 3.3 V to 1% target
Freq.
tCPU-PCI
VT = 50% to 1.5V
1 Guaranteed by design, not 100% tested in production.
0445B—08/01/03
8
1
2.85
ICS94225
Electrical Characteristics - USB, REF(1:0)
TA = 0 - 70°C; VDD = 3.3 V +/-5%; CL = 20 pF (unless otherwise stated)
PARAMETER
SYMBOL
CONDITIONS
MIN
VOH5
IOH = -12 mA
Output High Voltage
2.4
IOL = 9 mA
VOL5
Output Low Voltage
V
I
Output High Current
OH5
OH = 2.0 V
IOL5
VOL = 0.8 V
Output Low Current
16
1
tr5
VOL = 0.4 V, VOH = 2.4 V
Rise Time
1
tf5
VOH = 2.4 V, VOL = 0.4 V
Fall Time
1
dt5
VT = 1.5V
45
Duty Cycle
0.98
0.77
54
4
4
57
UNITS
V
V
mA
mA
ns
ns
%
Jitter, Cycle-to-cycle1
471
1100
ps
MAX
UNITS
1.2
0.4
V
V
mA
ns
ns
V
V
mV
%
ps
ps
ps
tjcyc-cyc2B
TYP
MAX
0.4
-22
VT = 1.5V
1Guaranteed by design, not 100% tested in production.
Electrical Characteristics - CPUCLK (Open Drain)
TA = 0 - 70°C; VDD = 3.3 V +/-5%; CL = 20 pF (unless otherwise stated)
PARAMETER
SYMBOL
CONDITIONS
VO = VX
Z0
Output Impedance
VOH2B
Output High Voltage
Termination to Vpull-up(external)
VOL2B
Output Low Voltage
VOL = 0.3 V
IOL2B
Output Low Current
tr2B
VOL = 0.3 V, VOH = 1.2 V
Rise Time1
VOH = 1.2 V, VOL = 0.3 V
tf2B
Fall Time1
1
V
Note 2
Differential voltage-AC
DIF
1
VDIF
Note 2
Differential voltage-DC
VX
Note 3
Differential Crossover
1
dt2B
VT = 50%
Duty Cycle
1
t
VT = 50%
Skew
sk2B
1
tjcyc-cyc2B
VT = VX
Jitter, Cycle-to-cycle
Jitter, Absolute1
tjabs2B
VT = 50%
MIN
TYP
1
18
0.4
0.2
550
45
-250
0.9
0.9
Vpu
+0.6
51
46
86
1100
55
200
250
250
Notes:
1 - Guaranteed by design, not 100% tested in production.
2 - VDIF specifies the minimum input differential voltages (VTR-VCP) required for switching, where VTR is the "true"
input level and VCP is the "complement" input level.
3 - Vpullup(external) = 1.5V, Min = Vpullup(external)/2-150mV; Max=(Vpullup(external)/2)+150mV
0445B—08/01/03
9
ICS94225
Electrical Characteristics - PCICLK_F, PCICLK(6:0)
TA = 0 - 70°C; VDD = 3.3 V +/-5%; CL = 20 pF (unless otherwise stated)
PARAMETER
SYMBOL
CONDITIONS
MIN
VOH5
IOH = -11 mA
Output High Voltage
2.6
IOL = 9.4 mA
VOL5
Output Low Voltage
VOH = 2.0 V
I
Output High Current
OH5
IOL5
VOL = 0.8 V
Output Low Current
19
1
tr5
VOL = 0.4 V, VOH = 2.4 V
Rise Time
1
tf5
VOH = 2.4 V, VOL = 0.4 V
Fall Time
1
dt5
VT = 1.5V
45
Duty Cycle
1
tsk2B
VT = 1.5V
Skew
1.8
1.8
51.7
175
2
2
55
200
UNITS
V
V
mA
mA
ns
ns
%
ps
Jitter, Cycle-to-cycle1
122
500
ps
TYP
MAX
tjcyc-cyc2B
VT = 1.5V
TYP
MAX
0.4
-16
1
Guaranteed by design, not 100% tested in production.
Electrical Characteristics - PCICLK_F, PCICLK(6:0)
TA = 0 - 70°C; VDD = 3.3 V +/-5%; CL = 20 pF (unless otherwise stated)
PARAMETER
SYMBOL
CONDITIONS
MIN
V
I
=
-11
mA
Output High Voltage
2.6
OH5
OH
VOL5
IOL = 9.4 mA
Output Low Voltage
VOH = 2.0 V
IOH5
Output High Current
IOL5
VOL = 0.8 V
Output Low Current
19
1
tr5
VOL = 0.4 V, VOH = 2.4 V
Rise Time
1
tf5
VOH = 2.4 V, VOL = 0.4 V
Fall Time
1
dt5
VT = 1.5V
45
Duty Cycle
1
tsk2B
VT = 1.5V
Skew
1.8
1.8
51.7
175
2
2
55
200
UNITS
V
V
mA
mA
ns
ns
%
ps
Jitter, Cycle-to-cycle1
122
500
ps
tjcyc-cyc2B
VT = 1.5V
1
Guaranteed by design, not 100% tested in production.
0445B—08/01/03
10
0.4
-16
ICS94225
Electrical Characteristics - AGP(1:0)
TA = 0 - 70°C; VDD = 3.3 V +/-5%; CL = 20 pF (unless otherwise stated)
PARAMETER
SYMBOL
CONDITIONS
MIN
Output High Voltage
VOH5
IOH = -18 mA
2.6
Output Low Voltage
VOL5
IOL = 1.8 mA
VOH = 2.0 V
Output High Current
IOH5
VOL = 0.8 V
19
Output Low Current
IOL5
1
Rise Time
tr5
VOL = 0.4 V, VOH = 2.4 V
Fall Time1
tf5
VOH = 2.4 V, VOL = 0.4 V
1
Duty Cycle
dt5
VT = 50%
45
1
1
Skew (window)
Tsk
VT = 50%
Jitter, Cycle-to-cycle1
tjcyc-cyc2B
VT = 50%
1
TYP
MAX
0.4
-16
1.05
1.27
50.4
12
268
1.6
1.6
55
200
500
UNITS
V
V
mA
mA
ns
ns
%
ps
ps
Guaranteed by design, not 100% tested in production.
Electrical Characteristics - SDRAM_OUT
TA = 0 - 70°C; VDD = 3.3 V +/-5%; CL = 20 pF (unless otherwise stated)
PARAMETER
SYMBOL
CONDITIONS
Output High Voltage
VOH3
IOH = -11 mA
Output Low Voltage
VOL3
IOL = 11 mA
Output High Current
IOH3
VOH = 2.0 V
VOL = 0.8 V
Output Low Current
IOL3
1
Rise Time
tr3
VOL = 0.4 V, VOH = 2.4 V@100MHz
1
Fall Time
tf3
VOH = 2.4 V, VOL = 0.4 V@100MHz
1
Duty Cycle
dt3
VT = 50%
1
Jitter, Cycle-to-cycle
tjcyc-cyc3B
VT = 50% @ 100MHz
1
Guaranteed by design, not 100% tested in production.
0445B—08/01/03
11
MIN
2
TYP
MAX
0.4
-12
12
45
0.83
0.71
50.8
240
1.6
1.6
55
250
UNITS
V
V
mA
mA
ns
ns
%
ps
ICS94225
General I2C serial interface information for the ICS94225
How to Write:
How to Read:
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
Controller (host) sends a start bit.
Controller (host) sends the write address D2 (H)
ICS clock will acknowledge
Controller (host) sends a dummy command code
ICS clock will acknowledge
Controller (host) sends a dummy byte count
ICS clock will acknowledge
Controller (host) starts sending Byte 0 through Byte 20
(see Note)
• ICS clock will acknowledge each byte one at a time
• Controller (host) sends a Stop bit
Controller (host) will send start bit.
Controller (host) sends the read address D3 (H)
ICS clock will acknowledge
ICS clock will send the byte count
Controller (host) acknowledges
ICS clock sends Byte 0 through byte 8 (default)
ICS clock sends Byte 0 through byte X (if X(H) was
written to byte 8).
• Controller (host) will need to acknowledge each byte
• Controller (host) will send a stop bit
How to Read:
How to Write:
Controller (Host)
Start Bit
Address D2(H)
Controller (Host)
Start Bit
Address D3(H)
ICS (Slave/Receiver)
ICS (Slave/Receiver)
ACK
Byte Count
ACK
Dummy Command Code
ACK
ACK
ACK
ACK
ACK
ACK
ACK
ACK
ACK
ACK
ACK
ACK
ACK
ACK
ACK
ACK
If 7H has been written to B6
ACK
Byte 0
Dummy Byte Count
Byte 1
Byte 0
Byte 2
Byte 1
Byte 3
Byte 2
Byte 4
Byte 3
Byte 5
Byte 4
Byte 6
Byte 5
Byte 6
ACK
Byte 7
Byte 18
ACK
If 12H has been written to B6
ACK
If 13H has been written to B6
ACK
If 14H has been written to B6
ACK
Stop Bit
Byte 19
ACK
Byte 20
ACK
Stop Bit
*See notes on the following page.
0445B—08/01/03
12
Byte18
Byte 19
Byte 20
ICS94225
Brief I2C registers description for ICS94225
Programmable System Frequency Generator
Register Name
Functionality &
Frequency Select
Register
Byte
0
Output Control Registers
1-6
Vendor ID & Revision ID
Registers
7
Byte Count
Read Back Register
8
Watchdog Timer
Count Register
9
Watchdog Control
Registers
10 Bit [6:0]
Description
Output frequency, hardware / I2C
frequency select, spread spectrum &
output enable control register.
Active / inactive output control
registers/latch inputs read back.
Byte 11 bit[7:4] is ICS vendor id 1001. Other bits in this register
designate device revision ID of this
part.
Writing to this register will configure
byte count and how many byte will
be read back. Do not write 00H to
this byte.
Writing to this register will configure
the number of seconds for the
watchdog timer to reset.
Watchdog enable, watchdog status
and programmable 'safe' frequency'
can be configured in this register.
This bit select whether the output
frequency is control by
hardware/byte 0 configurations or
byte 11&12 programming.
These registers control the dividers
ratio into the phase detector and
thus control the VCO output
frequency.
VCO Control Selection
Bit
10 Bit [7]
VCO Frequency Control
Registers
11-12
Spread Spectrum
Control Registers
13-14
These registers control the spread
percentage amount.
Group Skews Control
Registers
15-16
Increment or decrement the group
skew amount as compared to the
initial skew.
Output Rise/Fall Time
Select Registers
17-20
These registers will control the
output rise and fall time.
Notes:
1.
2.
3.
4.
5.
6.
7.
PWD Default
See individual
byte
description
See individual
byte
description
See individual
byte
description
08H
10H
000,0000
0
Depended on
hardware/byte
0 configuration
Depended on
hardware/byte
0 configuration
See individual
byte
description
See individual
byte
description
The ICS clock generator is a slave/receiver, I2C component. It can read back the data stored in the latches
for verification. Readback will support standard SMBUS controller protocol. The number of bytes to
readback is defined by writing to byte 8.
When writing to byte 11 - 12, and byte 13 - 14, they must be written as a set. If for example, only byte
14 is written but not 15, neither byte 14 or 15 will load into the receiver.
The data transfer rate supported by this clock generator is 100K bits/sec or less (standard mode)
The input is operating at 3.3V logic levels.
The data byte format is 8 bit bytes.
To simplify the clock generator I2C interface, the protocol is set to use only Block-Writes from the
controller. The bytes must be accessed in sequential order from lowest to highest byte with the ability to
stop after any complete byte has been transferred. The Command code and Byte count shown above must
be sent, but the data is ignored for those two bytes. The data is loaded until a Stop sequence is issued.
At power-on, all registers are set to a default condition, as shown.
0445B—08/01/03
13
ICS94225
Shared Pin Operation Input/Output Pins
Figure 1 shows a means of implementing this function
when a switch or 2 pin header is used. With no jumper is
installed the pin will be pulled high. With the jumper in
place the pin will be pulled low. If programmability is not
necessary, than only a single resistor is necessary. The
programming resistors should be located close to the
series termination resistor to minimize the current loop
area. It is more important to locate the series termination
resistor close to the driver than the programming resistor.
The I/O pins designated by (input/output) serve as dual
signal functions to the device. During initial power-up,
they act as input pins. The logic level (voltage) that is
present on these pins at this time is read and stored into
a 5-bit internal data latch. At the end of Power-On reset,
(see AC characteristics for timing values), the device
changes the mode of operations for these pins to an
output function. In this mode the pins produce the
specified buffered clocks to external loads.
To program (load) the internal configuration register for
these pins, a resistor is connected to either the VDD
(logic 1) power supply or the GND (logic 0) voltage
potential. A 10 Kilohm (10K) resistor is used to provide
both the solid CMOS programming voltage needed during
the power-up programming period and to provide an
insignificant load on the output clock during the subsequent
operating period.
Fig. 1
0445B—08/01/03
14
ICS94225
CPU_STOP# Timing Diagram
CPU_STOP# is an asychronous input to the clock synthesizer. It is used to turn off the CPUCLKs for low power
operation. CPU_STOP# is synchronized by the ICS94225. All other clocks will continue to run while the CPUCLKs
clocks are disabled. The CPUCLKs will always be stopped in a low state and start in such a manner that guarantees
the high pulse width is a full pulse. CPUCLK on latency is less than 4 CPUCLKs and CPUCLK off latency is less than
4 CPUCLKs.
INTERNAL
CPUCLK
PCICLK
CPU_STOP#
PD# (High)
CPUCLKT
CPUCLKC
Notes:
1. All timing is referenced to the internal CPUCLK.
2. CPU_STOP# is an asynchronous input and metastable conditions may exist. This signal is
synchronized to the CPUCLKs inside the ICS94225.
3. All other clocks continue to run undisturbed.
4. PD# and PCI_STOP# are shown in a high (true) state.
0445B—08/01/03
15
ICS94225
PCI_STOP# Timing Diagram
PCI_STOP# is an asynchronous input to the ICS94225. It is used to turn off the PCICLK clocks for low power operation.
PCI_STOP# is synchronized by the ICS94225 internally. PCICLK clocks are stopped in a low state and started with
a full high pulse width guaranteed. PCICLK clock on latency cycles are only one rising PCICLK clock off latency is one
PCICLK clock.
CPUCLK
(Internal)
PCICLK
(Internal)
PCICLK
(Free-runningl)
CPU_STOP#
PCI_STOP#
PWR_DWN#
PCICLK
(External)
Notes:
1. All timing is referenced to the Internal CPUCLK (defined as inside the ICS94225 device.)
2. PCI_STOP# is an asynchronous input, and metastable conditions may exist. This signal is required to be synchronized
inside the ICS94225.
3. All other clocks continue to run undisturbed.
4. PD# and CPU_STOP# are shown in a high (true) state.
0445B—08/01/03
16
ICS94225
PD# Timing Diagram
The power down selection is used to put the part into a very low power state without turning off the power to the part.
PD# is an asynchronous active low input. This signal needs to be synchronized internal to the device prior to powering
down the clock synthesizer.
Internal clocks are not running after the device is put in power down. When PD# is active low all clocks need to be driven
to a low value and held prior to turning off the VCOs and crystal. The power up latency needs to be less than 3 mS.
The power down latency should be as short as possible but conforming to the sequence requirements shown below.
PCI_STOP# and CPU_STOP# are considered to be don't cares during the power down operations. The REF and 48MHz
clocks are expected to be stopped in the LOW state as soon as possible. Due to the state of the internal logic, stopping
and holding the REF clock outputs in the LOW state may require more than one clock cycle to complete.
PD#
CPUCLKT
CPUCLKC
PCICLK
VCO
Crystal
Notes:
1. All timing is referenced to the Internal CPUCLK (defined as inside the ICS94225 device).
2. As shown, the outputs Stop Low on the next falling edge after PD# goes low.
3. PD# is an asynchronous input and metastable conditions may exist. This signal is synchronized inside this part.
4. The shaded sections on the VCO and the Crystal signals indicate an active clock.
5. Diagrams shown with respect to 133MHz. Similar operation when CPU is 100MHz.
0445B—08/01/03
17
ICS94225
c
N
L
E1
INDEX
AREA
SYMBOL
A
A1
b
c
D
E
E1
e
h
L
N
α
E
1 2
a
h x 45°
D
A
A1
-Ce
N
SEATING
PLANE
b
.10 (.004) C
48
In Millimeters
COMMON DIMENSIONS
MIN
MAX
2.41
2.80
0.20
0.40
0.20
0.34
0.13
0.25
SEE VARIATIONS
10.03
10.68
7.40
7.60
0.635 BASIC
0.38
0.64
0.50
1.02
SEE VARIATIONS
0°
8°
In Inches
COMMON DIMENSIONS
MIN
MAX
.095
.110
.008
.016
.008
.0135
.005
.010
SEE VARIATIONS
.395
.420
.291
.299
0.025 BASIC
.015
.025
.020
.040
SEE VARIATIONS
0°
8°
VARIATIONS
D mm.
MIN
MAX
15.75
16.00
D (inch)
MIN
.620
Reference Doc.: JEDEC Publication 95, MO-118
10-0034
300 mil SSOP Package
Ordering Information
ICS94225yF-T
Example:
ICS XXXX y F - PPP - T
Designation for tape and reel packaging
Pattern Number (2 or 3 digit number for parts with ROM code
patterns)
Package Type
F=SSOP
Revision Designator (will not correlate with datasheet revision)
Device Type
Prefix
ICS, AV = Standard Device
0445B—08/01/03
18
MAX
.630