IDT ICS951702

ICS951702
Integrated
Circuit
Systems, Inc.
Advance Information
PIII™ System Clock Chip for DDR SDRAM
Recommended Application:
1644 and 1644T applications using DDR
Output Features:
•
7 - Differential pairs DDR SDRAM clocks
•
3 - CPU @ 2.5V (1 - Free running)
•
8 - PCI @ 3.3V (1 - Free running and 1 - 2 X optional)
•
2 - AGP @ 3.3V
•
1 - IOAPIC @ 2.5V
•
1 - 48MHz, @3.3V
•
1 - REF @ 3.3V
Features:
•
Up to 147MHz frequency support
•
Power management through PD#
•
Spread spectrum for EMI control (0 to -0.5% down
spread, ± 0.25% center spread).
•
Uses external 14.318MHz crystal
Skew Specifications:
•
CPU - CPU: <250ps
•
PCI - PCI: <500ps
•
SDRAM - SDRAM: <250ps
•
AGP - AGP: <250ps
•
PCI - AGP: <750ps
•
CPU - SDRAM: <750ps
•
CPU - PCI: <3ns
VDDL
IOAPIC
GND
X1
X2
AVDD
**FS0/REF
VDD
**FS1/AGP0
AGP1
GND
**FS2/PCI_F
PCICLK0
PCICLK1
PCICLK2
GND
VDD
PCICLK3
PCICLK4
PCICLK5
GND
VDD
1
PCICLK6
*PCI_STOP#
*CPU_STOP#
*Vtt_PWRGD/PD#
VDD
**FS3/48MHz
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
ICS951702
Pin Configuration
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
VDDL
CPUCLK_F
CPUCLK0
CPUCLK1
GND
DDRT0
DDRC0
GND
VDDL
DDRT1
DDRC1
DDRT2
DDRC2
VDDL
GND
DDRT3
DDRC3
DDRT4
DDRC4
GND
VDDL
DDRT5
DDRC5
DDRT6
DDRC6
SCLK
SDATA
GND
56-Pin 240 mil TSSOP
Notes:
* Internal Pull-up Resistor of 120K to VDD
** Internal Pull-down of 120K to GND
1. PCICLK6 is selectable 2X via I2C
Functionality
Block Diagram
PLL2
X1
X2
48MHz
XTAL
OSC
REF0
IOAPIC
PLL1
Spread
Spectrum
CPU
DIVDER
Stop
2
CPUCLK_F
SDRAM
DIVDER
Vtt_PWRGD/PD#
MODE
SDATA
SCLK
FS (3:0)
7
PCI
DIVDER
Stop
5
DDRC (6:0)
DDRT (6:0)
PCICLK (6:0)
PCICLK_F
Config.
Reg.
0664—07/29/02
7
Control
Logic
CPUCLK (1:0)
AGP
DIVDER
2
AGP (1:0)
FS3
0
0
0
0
0
0
0
0
1
1
1
1
1
1
1
1
FS2
0
0
0
0
1
1
1
1
0
0
0
0
1
1
1
1
FS1
0
0
1
1
0
0
1
1
0
0
1
1
0
0
1
1
FS0
0
1
0
1
0
1
0
1
0
1
0
1
0
1
0
1
CPU SDRAM
66.66
66.66
66.66 100.00
100.00 66.66
100.00 100.00
100.00 133.33
133.33 66.66
133.33 100.00
133.33 133.33
66.66
66.66
66.66 100.00
100.00 66.66
100.00 100.00
100.00 133.33
133.33 66.66
133.33 100.00
133.33 133.33
Note:
PCICLK = 33.33MHz
AGP = 66.66MHz
ADVANCE INFORMATION documents contain information on products in the formative or design phase development. Characteristic data and other specifications are design goals.
ICS reserves the right to change or discontinue these products without notice. Third party brands and names are the property of their respective owners.
ICS951702
Advance Information
Pin Descriptions
PIN NUMBER
PIN NAME
TYPE
1, 36, 43, 48, 56
VDDL
PWR
Power supply pins, nominal 2.5V
2
3, 11, 16, 21,
29, 37, 42, 49,
52
4
5
6
IOAPIC
OUT
2.5V clock outputs
GND
PWR
Ground pins
X1
X2
AVDD
IN
OUT
PWR
IN
OUT
PWR
Crystal input,nominally 14.318MHz.
Crystal output, nominally 14.318MHz.
Analog power supply for 3.3V
Frequency select pin.
14.318 MHz reference clock.
Power supply pins, nominal 3.3V
FS21, 2
IN
OUT
OUT
OUT
IN
Frequency select pin.
AGP outputs defined as 2X PCI.
AGP output defined as 2X PCI.
Free running PCI clock
Frequency select pin.
PCICLK (5:0)
OUT
PCI clock outputs.
PCICLK6
OUT
24
PCI_STOP#
IN
25
CPU_STOP#
IN
PD#
IN
Vtt_PWRGD
IN
FS32, 3
48MHz
SDATA
SCLK
IN
OUT
I/O
IN
PCI clock output (selectable 1X or 2X via I2C)
Stops all PCICLKs at logic 0 level, when input low besides the
PCICLK_F clocks which are controllable by I2C bits whether they are
free running or stopped by PCI_STOP.
Stops all CPUCLKs at logic 0 level, when input low. The individual
CPU clocks are controllable by I2C bits whether they are free
running or stopped by CPU_STOP.
Asynchronous active low input pin used to power down the device
into a low power state. The internal clocks are disabled and the
VCO and the crystal are stopped. The latency of the power down will
not be greater than 3ms.
This pin acts as a dual function input pin for Vtt_PWRGD and PD#
signal. When Vtt_PWRGD goes high the frequency select will be
latched at power on thereafter the pin is an asynchronous active low
power down pin.
Frequency select pin
48MHz output clock
DDRT (6:0)
OUT
DDRC (6:0)
OUT
CPUCLK (1:0)
CPUCLK_F
OUT
OUT
7
8, 17, 22, 27
9
10
12
20, 19, 18, 15,
14, 13
23
FS02, 3
REF0
VDD
FS12, 3
AGP0
AGP1
PCICLK_F
26
28
30
31
33, 35, 39, 41,
45, 47, 51
32, 34, 38, 40,
44, 46, 50
53, 54
55
DESCRIPTION
Data pin for I2C circuitry 5V tolerant
Clock pin of I2C circuitry 5V tolerant
"True" clocks of differential pair DDR SDRAM outputs - 2.5V
"Complementry" clocks of differential pair
DDR SDRAM outputs - 2.5V
2.5V CPU clocks
Free running CPU clock. Not affected by the CPU_STOP#.
Notes:
1: Internal Pull-up Resistor of 120K to 3.3V on indicated inputs
2: Internal pull-down resistor of 120K to GND on indicated inputs.
3: Bidirectional input/output pins, input logic levels are latched at internal power-on-reset. Use
10Kohm resistor to program logic Hi to VDD or GND for logic low.
0664—07/29/02
2
ICS951702
Advance Information
General Description
The ICS951702 is a main clock synthesizer chip for PIII based systems with ALI 1644 style chipset. This provides all
clocks required for such a system.
Spread spectrum may be enabled through I2C programming. Spread spectrum typically reduces system EMI by 8dB
to 10dB. This simplifies EMI qualification without resorting to board design iterations or costly shielding. The ICS951702
employs a proprietary closed loop design, which tightly controls the percentage of spreading over process and
temperature variations.
Serial programming I2C interface allows changing functions, stop clock programming and frequency selection.
Mode Pin - Power Management Input Control
STATE
0
1
Pin 24
Pin 25
Pin 26
PCI_STOP#
(Input)
PCICLK4
(Output, Active)
CPU_STOP#
(Input)
CPUCLKs
(Output, Active)
PD#
(Input)
Power Groups
AVDD = PLL Core & Xtal
VDD48 = 48MHz, PLL2
VDDL, VDD = Digital
0664—07/29/02
3
Active
ICS951702
Advance Information
Serial Configuration Command Bitmap
Byte0: Functionality and Frequency Select Register (default = 0)
Bit
Description
FS3 FS2 FS1 FS0 CPUCLK SDRAM PCICLK AGP
(MHz)
(MHz)
(MHz) (MHz)
Bit2 Bit7 Bit6 Bit5 Bit4
0
0
0
0
0
66.66
66.66
33.33
66.66
0
0
0
0
1
66.66
100.00
33.33
66.66
0
0
0
1
0
100.00
66.66
33.33
66.66
0
0
0
1
1
100.00
100.00
33.33
66.66
0
0
1
0
0
100.00
133.33
33.33
66.66
0
0
1
0
1
133.33
66.66
33.33
66.66
0
0
1
1
0
133.33
100.00
33.33
66.66
0
0
1
1
1
133.33
133.33
33.33
66.66
0
1
0
0
0
66.66
66.66
33.33
66.66
0
1
0
0
1
66.66
100.00
33.33
66.66
0
1
0
1
0
100.00
66.66
33.33
66.66
0
1
0
1
1
100.00
100.00
33.33
66.66
0
1
1
0
0
100.00
133.33
33.33
66.66
0
1
1
0
1
133.33
66.66
33.33
66.66
0
1
1
1
0
133.33
100.00
33.33
66.66
Bit 2,
Bit 7:4
0
1
1
1
1
133.33
133.33
33.33
66.66
1
0
0
0
0
69.99
69.99
35.00
69.99
1
0
0
0
1
69.99
105.00
35.00
69.99
1
0
0
1
0
105.00
69.99
35.00
69.99
1
0
0
1
1
105.00
105.00
35.00
69.99
1
0
1
0
0
105.00
140.00
35.00
69.99
1
0
1
0
1
140.00
69.99
35.00
69.99
1
0
1
1
0
140.00
105.00
35.00
69.99
1
0
1
1
1
140.00
140.00
35.00
69.99
1
1
0
0
0
73.33
73.33
36.66
73.33
1
1
0
0
1
73.33
110.00
36.66
73.33
1
1
0
1
0
110.00
73.33
36.66
73.33
1
1
0
1
1
110.00
110.00
36.66
73.33
1
1
1
0
0
110.00
146.66
36.66
73.33
1
1
1
0
1
146.66
73.33
36.66
73.33
1
1
1
1
0
146.66
110.00
36.66
73.33
1
1
1
1
1
146.66
146.66
36.66
73.33
0
F
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q
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c
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c
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d
b
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h
a
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d
w
a
r
e
s
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l
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c
t
,
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h
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I
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p
u
t
s
Bit 3 1 - Frequency is selected by Bit 2, 7:4
0 - Normal
Bit 1 1 - Spread Spectrum Enabled
unning
Bit 0 10- -TR
ristate all outputs
PWD
Spread Precentage
+/- 0.25% Center Spread
+/- 0.25% Center Spread
+/- 0.25% Center Spread
+/- 0.25% Center Spread
+/- 0.25% Center Spread
+/- 0.25% Center Spread
+/- 0.25% Center Spread
+/- 0.25% Center Spread
0 to -0.5% Down Spread
0 to -0.5% Down Spread
0 to -0.5% Down Spread
0 to -0.5% Down Spread
0 to -0.5% Down Spread
0 to -0.5% Down Spread
0 to -0.5% Down Spread
0 to -0.5% Down Spread
+/- 0.25% Center Spread
+/- 0.25% Center Spread
+/- 0.25% Center Spread
+/- 0.25% Center Spread
+/- 0.25% Center Spread
+/- 0.25% Center Spread
+/- 0.25% Center Spread
+/- 0.25% Center Spread
+/- 0.25% Center Spread
+/- 0.25% Center Spread
+/- 0.25% Center Spread
+/- 0.25% Center Spread
+/- 0.25% Center Spread
+/- 0.25% Center Spread
+/- 0.25% Center Spread
+/- 0.25% Center Spread
Note1: Default at power-up will be for latched logic inputs to define frequency, as displayed by Bit 3.
The I2C readback of the power up default indicates the revision ID in bits 2, 7:4 as shown.
0664—07/29/02
4
00000
Note1
0
0
0
ICS951702
Advance Information
Byte 1: Active/Inactive Register
(1= enable, 0 = disable)
BIT
PIN# PWD
Bit 7
-
X
Bit 6
10
Bit 5
9
Bit 4
28
Bit 3
2
Bit 2
Byte 2: Active/Inactive Register
(1= enable, 0 = disable)
DESCRIPTION
BIT
PIN# PWD
DESCRIPTION
FS3#
Bit 7
13
1
PCICLK0
1
AGP1
Bit 6
14
1
PCICLK1
1
AGP0
Bit 5
15
1
PCICLK2
1
48MHz
Bit 4
18
1
PCICLK3
1
IOAPIC
Bit 3
19
1
PCICLK4
55
1
CPUCLK_F
Bit 2
51, 50
1
SDRAMT0, SDRAMC0
Bit 1
54
1
CPUCLK0
Bit 1
47, 46
1
SDRAMT1, SDRAMC1
Bit 0
53
1
CPUCLK1
Bit 0
45, 44
1
SDRAMT2, SDRAMC2
Byte 3: Active/Inactive Register
(1= enable, 0 = disable)
BIT
PIN#
PWD
Byte 4: Active/Inactive Register
(1= enable, 0 = disable)
BIT
DESCRIPTION
PIN# PWD
DESCRIPTION
Bit 7
-
X
FS0#
Bit 7
Bit 6
-
X
FS1#
Bit 6
20
1
PCICLK5
Bit 5
-
X
FS2#
PCICLK6
Bit 4
12
1
PCICLK_F
Bit 3
-
1
Reserved
Bit 2
39, 38
1
SDRAMT3, SDRAMC3
Bit 1
35, 34
1
SDRAMT4, SDRAMC4
Bit 0
33, 32
1
SDRAMT5, SDRAMC5
BIT
PIN# PWD
1
Reser ved
Bit 5
23
1
Bit 4
23
1
PCICLK6; 1=1X, 0=2X
Bit 3
-
1
Reser ved
Bit 2
-
1
Reser ved
Bit 1
33,
32
1
Reser ved
1
SDRAMT6, SDRAMC6
Bit 0
Byte 5: Active/Inactive Register
(1= enable, 0 = disable)
-
Byte 6: Active/Inactive Register
(1= enable, 0 = disable)
DESCRIPTION
BIT
PIN# PWD
DESCRIPTION
Bit 7
-
1
Reser ved
Bit 7
-
0
Reser ved
Bit 6
-
1
Reser ved
Bit 6
-
0
Reser ved
Bit 5
-
1
Reser ved
Bit 5
-
0
Reser ved
Bit 4
-
1
Reser ved
Bit 4
-
0
Reser ved
Bit 3
-
1
Reser ved
Bit 3
-
0
Reser ved
Bit 2
-
1
Reser ved
Bit 2
-
1
Reser ved
Bit 1
-
1
Reser ved
Bit 1
-
1
Reser ved
Bit 0
-
1
Reser ved
Bit 0
-
1
Reser ved
Note: Don’t write into this register, writing into this
register can cause malfunction
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.
0664—07/29/02
5
ICS951702
Advance Information
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
Case Temperature . . . . . . . . . . . . . . . . . . . . . . 115°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 - 70º C; Supply Voltage VDD = 3.3V, VDDL = 2.5 V +/-5% (unless otherwise stated)
PARAMETER
Input High Voltage
Input Low Voltage
Input High Current
Input Low Current
Input Low Current
Operating
Supply Current
Input frequency
Input Capacitance1
Clk Stabilization1
SYMBOL
V IH
VIL
IIH
IIL1
IIL2
IDD3.3OP66
IDD3.3OP100
Fi
CIN
CINX
TSTAB
CONDITIONS
VIN = VDD
VIN = 0 V; Inputs with no pull-up resistors
VIN = 0 V; Inputs with pull-up resistors
CL = 0 pF; Select @ 66MHz
CL = 0 pF; Select @ 100MHz
VDD = 3.3 V;
Logic Inputs
X1 & X2 pins
From VDD = 3.3 V to 1% target Freq.
1
Guaranteed by design, not 100% tested in production.
0664—07/29/02
6
MIN
TYP
2
VSS-0.3
-5
-200
12
27
MAX UNITS
V DD+0.3 V
0.8
V
5
mA
mA
mA
77
mA
100
16
MHz
5
45
pF
pF
3
ms
ICS951702
Advance Information
Electrical Characteristics - CPUCLK
TA = 0 - 70º C; VDD = 3.3 V +/-5%, VDDL = 2.5 V +/-5%; CL = 20 pF (unless otherwise stated)
PARAMETER
Output High Voltage
Output Low Voltage
Output High Current
Output Low Current
SYMBOL
VOH2B
VOL2B
I OH2B
IOL2B
CONDITIONS
IOH = -12.0 mA
IOL = 12 mA
VOH = 1.7 V
VOL = 0.7 V
MIN
2
TYP
19
MAX UNITS
V
0.4
V
-19
mA
mA
tr2B
1
VOL = 0.4 V, VOH = 2.0 V
1.6
ns
Fall Time
tf2B
1
VOH = 2.0 V, V OL = 0.4 V
1.6
ns
Duty Cycle
dt2B1
tsk2B1
Rise Time
55
%
VT = 1.25 V
250
ps
Jitter, Cycle-to-cycle t jcyc-cyc2B1 VT = 1.25 V
VT = 1.25 V
tj1s2B1
Jitter, One Sigma
250
ps
150
ps
Skew
VT = 1.25 V
45
1
Guaranteed by design, not 100% tested in production.
Electrical Characteristics - PCICLK
TA = 0 - 70º C; VDD = 3.3 V +/-5%, VDDL = 2.5 V +/-5%; CL = 30 pF (unless otherwise stated)
PARAMETER
Output High Voltage
Output Low Voltage
Output High Current
Output Low Current
Rise Time1
SYMBOL
VOH1
VOL1
IOH1
I OL1
CONDITIONS
I OH = -11 mA
I OL = 9.4 mA
VOH = 2.0 V
VOL = 0.8 V
MIN
2.4
25
TYP
MAX UNITS
V
0.4
V
-22
mA
mA
tr1
VOL = 0.4 V, VOH = 2.4 V
2
ns
tf1
VOH = 2.4 V, VOL = 0.4 V
2
ns
Duty Cycle
dt1
VT = 1.5 V
55
%
Skew1
tsk1
VT = 1.5 V
500
ps
Jitter, Cycle-to-cycle tjcyc-cyc2B1 VT = 1.5 V
Jitter, One Sigma1
t j1s1
VT = 1.5 V
1
Jitter, Absolute
t jabs1
VT = 1.5 V
250
ps
150
ps
500
ps
1
Fall Time
1
1
45
-500
Guaranteed by design, not 100% tested in production.
0664—07/29/02
7
ICS951702
Advance Information
Electrical Characteristics - SDRAMT & C
TA = 0 - 70º C; VDD = 3.3 V +/-5%, VDDL = 2.5 V +/-5%; CL = 20 pF (unless otherwise stated)
PARAMETER
Output High Voltage
Output Low Voltage
Output High Current
Output Low Current
SYMBOL
VOH2B
VOL2B
IOH2B
I OL2B
Rise Time
t r2B1
t f2B1
dt2B1
t sk2B1
Fall Time
CONDITIONS
I OH = -12.0 mA
I OL = 12 mA
VOH = 1.7 V
VOL = 0.7 V
MIN
2
TYP
19
MAX UNITS
V
0.4
V
-19
mA
mA
VOL = 0.4 V, VOH = 2.0 V
1.6
ns
VOH = 2.0 V, VOL = 0.4 V
1.6
ns
53
%
VT = 1.25 V
250
ps
Jitter, Cycle-to-cycle t jcyc-cyc2B1 VT = 1.25 V
t j1s2B1
VT = 1.25 V
Jitter, One Sigma
250
ps
150
ps
Duty Cycle
Skew
VT = 1.25 V
47
1
Guaranteed by design, not 100% tested in production.
Electrical Characteristics - IOAPIC
TA = 0 - 70º C; VDD = 3.3 V +/-5%, VDDL = 2.5 V +/-5%; CL = 20 pF (unless otherwise stated)
PARAMETER
Output High Voltage
Output Low Voltage
Output High Current
Output Low Current
Rise Time1
1
Fall Time
1
Duty Cycle
1
Jitter, One Sigma
Jitter, Absolute1
SYMBOL
V OH4B
V OL4B
IOH4B
IOL4B
CONDITIONS
IOH = -12 mA
IOL = 12 mA
VOH = 1.7 V
VOL = 0.7 V
MIN
2
19
TYP
MAX UNITS
V
0.4
V
-19
mA
mA
Tr4B
VOL = 0.4 V, VOH = 2.0 V
2
ns
Tf4B
VOH = 2.0 V, VOL = 0.4 V
2
ns
Dt4B
VT = 1.25 V
45
55
%
Tj1s4B
Tjabs4B
VT = 1.25 V
VT = 1.25 V
-1
1
Guaranteed by design, not 100% tested in production.
0664—07/29/02
8
0.5
ns
1
ns
ICS951702
Advance Information
Electrical Characteristics - 24MHz, 48MHz, REF
TA = 0 - 70º C; V DD = 3.3 V +/-5%, VDDL = 2.5 V +/-5%; CL = 20 pF (unless otherwise stated)
PARAMETER
Output High Voltage
Output Low Voltage
Output High Current
Output Low Current
Rise Time1
SYMBOL
VOH5
VOL5
IOH5
I OL5
CONDITIONS
IOH = -16 mA
IOL = 9 mA
V OH = 2.0 V
V OL = 0.8 V
16
tr5
V OL = 0.4 V, V OH = 2.4 V
Fall Time1
tf5
V OH = 2.4 V, V OL = 0.4 V
Duty Cycle1
dt5
V T = 1.5 V
t j1s5
tjabs5
V T = 1.5 V
V T = 1.5 V
1
Jitter, One Sigma
Jitter, Absolute1
MIN
2.4
45
-1
1
Guaranteed by design, not 100% tested in production.
0664—07/29/02
9
TYP
MAX UNITS
V
0.4
V
-22
mA
mA
2
ns
2
ns
55
%
0.5
ns
1
ns
ICS951702
Advance Information
General I2C serial interface information
The information in this section assumes familiarity with I2C programming.
For more information, contact ICS for an I2C programming application note.
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 first byte (Byte 0)
through byte 6
• 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 first byte (Byte 0) through byte 7
Controller (host) will need to acknowledge each byte
Controller (host) will send a stop bit
How to Read:
How to Write:
Controlle r (Host)
Start Bit
Address
D2(H )
Controlle r (Host)
Start Bit
Address
D3(H )
ICS (Sla ve/Re ceiver)
ICS (Sla ve/Re ceiver)
A CK
Byte Count
A CK
Dummy Command Code
A CK
ACK
A CK
ACK
A CK
ACK
A CK
ACK
A CK
ACK
A CK
ACK
A CK
ACK
A CK
ACK
A CK
Stop Bit
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 7
Byte 6
Byte 7
A CK
Stop Bit
Notes:
1.
2.
3.
4.
5.
6.
The ICS clock generator is a slave/receiver, I2C component. It can read back the data stored in the latches for
verification. Read-Back will support Intel PIIX4 "Block-Read" protocol.
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.
0664—07/29/02
10
ICS951702
Advance Information
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) on the ICS9248174 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.
Via to
VDD
Programming
Header
2K W
Via to Gnd
Device
Pad
8.2K W
Clock trace to load
Series Term. Res.
Fig. 1
0664—07/29/02
11
ICS951702
Advance Information
6.10 mm. Body, 0.50 mm. Pitch TSSOP
(240 mil)
(20 mil)
In Millimeters
In Inches
SYMBOL COMMON DIMENSIONS COMMON DIMENSIONS
MIN
MAX
MIN
MAX
A
-1.20
-.047
A1
0.05
0.15
.002
.006
A2
0.80
1.05
.032
.041
b
0.17
0.27
.007
.011
c
0.09
0.20
.0035
.008
SEE VARIATIONS
SEE VARIATIONS
D
8.10 BASIC
0.319 BASIC
E
E1
6.00
6.20
.236
.244
0.50 BASIC
0.020 BASIC
e
L
0.45
0.75
.018
.030
SEE VARIATIONS
SEE VARIATIONS
N
α
0°
8°
0°
8°
aaa
-0.10
-.004
c
N
L
E1
INDEX
AREA
E
1 2
D
A
A2
VARIATIONS
A1
N
-C-
e
b
SEATING
PLANE
56
D mm.
MIN
13.90
D (inch)
MAX
14.10
MIN
.547
Reference Doc.: JEDEC Publication 95, MO-153
10-0039
aaa C
Ordering Information
ICS951702yG-T
Example:
ICS XXXXXX y G - PPP - T
Designation for tape and reel packaging
Pattern Number (2 or 3 digit number for parts with ROM code
patterns)
Package Type
G=TSSOP
Revision Designator (will not correlate with datasheet revision)
Device Type
Prefix
ICS = Standard Device
0664—07/29/02
12
MAX
.555