ICS ICS94203

Integrated
Circuit
Systems, Inc.
ICS94203
Programmable System Frequency Generator for PII/III™
Pin Configuration
Output Features:
•
2 - CPUs @ 2.5V
•
13 - SDRAM @ 3.3V
•
3 - 3V66 @ 3.3V
•
7 - PCI @3.3V
•
1 - 24/48MHz@ 3.3V
•
1 - 48MHz @ 3.3V fixed
•
1 - REF @3.3V, 14.318MHz
Features:
•
Programmable ouput frequency
•
Gear ratio change detection
•
Real time system reset output
•
Spread spectrum for EMI control
with programmable spread percentage
•
Watchdog timer technology to reset system
if over-clocking causes malfunction.
•
Support power management through PD#.
•
Uses external 14.318MHz crystal
•
FS pins for frequency select
Key Specifications:
•
CPU Output Jitter: <250ps
•
IOAPIC Output Jitter: <500ps
•
48MHz, 3V66, PCI Output Jitter: <500ps
•
CPU Output Skew: <175ps
•
PCI Output Skew: <500ps
•
3V66 Output Skew <175ps
•
For group skew timing, please refer to the
Group Timing Relationship Table.
VDDA
GNDA
X1
X2
GND3V66
VDD3V66
3V66-0
3V66-1
3V66-2
VDDPCI
GNDPCI
1
*FS0/PCICLK0
1
*FS1/PCICLK1
1
*SEL24_48#/PCICLK2
GNDPCI
VDDPCI
PCICLK3
PCICLK4
PCICLK5
PCICLK6
RATIO_0
PD#
SCLK
SDATA
VDD48
GND48
*FS2/24_48MHz
1
*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
1
REF/FS4*
VDDLAPIC
1
IOAPIC0
VDDLCPU
GNDLCPU
CPUCLK0
CPUCLK1
GNDSDR
VDDSDR
SDRAM0
SDRAM1
SDRAM2
SDRAM3
VDDSDR
GNDSDR
SDRAM4
SDRAM5
SDRAM6
SDRAM7
SDRAM_F
GNDSDR
VDDSDR
SDRAM8
SDRAM9
SDRAM10
SDRAM11
RESET#
RATIO_1
56-Pin 300 mil SSOP
1. These pins will have 1.5 to 2X drive strength.
* 120K ohm pull-up to VDD on indicated inputs.
Block Diagram
PLL2
48MHz
24_48MHz
/2
X1
X2
XTAL
OSC
PLL1
Spread
Spectrum
REF
CPU
DIVDER
2
CPUCLK (1:0)
SDRAM
DIVDER
12
SDRAM (11:0)
SDRAM_F
Power Groups
VDDA, GNDA = Core PLL, Xtal
VDD48, GND48 = 48MHz, Fixed PLL
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
ICS94203
Recommended Application:
810/810E and Solano (815) type chipset
IOAPIC
DIVDER
FS(4:0)
PD#
SEL24_48#
SDATA
SCLK
IOAPIC
Control
Logic
PCI
DIVDER
7
Config.
3V66
DIVDER
3
PCICLK (6:0)
3V66 (2:0)
Reg.
RESET#
RATIO_0
RATIO_1
94203 Rev B 02/13/01
ICS reserves the right to make changes in the device data identified in
this publication without further notice. ICS advises its customers to
obtain the latest version of all device data to verify that any
information being relied upon by the customer is current and accurate.
ICS94203
General Description
The ICS94203 is a single chip clock solution for desktop designs using the 810/810E and Solano style chipset. It provides all necessary
clock signals for such a system.
The ICS94203 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.
Spread spectrum typically reduces system EMI by 7dB to 8dB. This simplifies EMI qualification without resorting to board design
iterations or costly shielding.
Pin Configuration
PIN NUMBER
P I N NA M E
TYPE
1, 6, 10, 16, 25,
35, 43, 48
VDD
PWR
3
X1
IN
4
X2
OUT
Crystal output, nominally 14.318MHz. Has internal load cap (33pF)
GND
PWR
Ground pins for 3.3V supply
3V66 [2:0]
OUT
3 . 3 V F i xe d 6 6 M H z c l o c k o u t p u t s f o r H U B
PCICLK01
OUT
3.3V PCI clock output, with Synchronous CPUCLKS
2, 5, 11, 15, 26,
36, 42, 49
9, 8, 7
12
DESCRIPTION
3.3V power supply
Crystal input, has internal load cap (33pF) and feedback
resistor from X2
FS0
IN
PCICLK11
OUT
FS1
IN
Logic input frequency select bit. Input latched at power on.
SEL24_48#
IN
2 4 / 4 8 M H z f r e q u e n cy s e l e c t p i n f o r p i n 2 7
PCICLK2
OUT
3.3V PCI clock output, with Synchronous CPUCLKS
20, 19, 18, 17
PCICLK [6:3]
OUT
3.3V PCI clock outputs, with Synchronous CPUCLKS
21
RATIO_0
OUT
Output to chipset, replacing the BSEL0 signals orginally from the processor.
22
PD#
IN
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.
23
SCLK
IN
Clock input of I2C input
24
SDATA
I/O
Data input for I2C serial input.
FS2
IN
Logic input frequency select bit. Input latched at power on.
24_48MHz
OUT
FS3
IN
48MHz
OUT
3 . 3 V F i xe d 4 8 M H z c l o c k o u t p u t f o r U S B .
29
RATIO_1
OUT
Output to chipset, replacing the BSE1 signals orginally from the processor.
30
RESET
OUT
37
31, 32, 33, 34,
38, 39, 40, 41,
44, 45, 46, 47
SDRAM_F
OUT
R e a l t i m e s y s t e m r e s e t s i g n a l f o r f r e q u e n cy r a t i o c h a n g e o r w a t c h d o g t i m m e r t i m e o u t .
This signal is active low.
3.3V SDRAM output can be turned off through I2C
SDRAM [11:0]
OUT
3.3V output. All SDRAM outputs can be turned off through I2C
13
Logic input frequency select bit. Input latched at power on.
3.3V PCI clock output, with Synchronous CPUCLKS
14
27
28
3 . 3 V 2 4 _ 4 8 M H z o u t p u t D e fa u l t i s 2 4 M H z .
Logic input frequency select bit. Input latched at power on.
50, 51
CPUCLK [1:0]
OUT
2.5V Host bus clock output. Output frequency derived from FS pins.
52
GNDL
PWR
Ground for 2.5V power supply for CPU & APIC
53, 55
VDDL
PWR
2.5V power suypply for CPU, IOAPIC
54
IOAPIC
OUT
2.5V clock outputs running at 16.67MHz.
56
FS4
IN
REF1
OUT
Logic input frequency select bit. Input latched at power on.
3.3V, 14.318MHz reference clock output.
2
ICS94203
General I2C serial interface information for the ICS94203
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 28
(see Note 2)
• 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 6 (default)
ICS clock sends Byte 0 through byte X (if X(H) was
written to byte 6).
• 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
Dummy Byte Count
Byte 0
Byte 0
Byte 1
Byte 1
Byte 2
Byte 2
Byte 3
Byte 3
Byte 4
Byte 4
Byte 5
Byte 5
Byte 6
Byte 6
ACK
Byte 7
Byte 26
ACK
If 1AH has been written to B6
ACK
If 1BH has been written to B6
ACK
If 1CH has been written to B6
ACK
Stop Bit
Byte 27
ACK
Byte 28
ACK
Stop Bit
*See notes on the following page.
3
Byte26
Byte 27
Byte 28
ICS94203
Brief I2C registers description for ICS94203
Programmable System Frequency Generator
Register Name
Functionality & Frequency Select
Register
Output Control Registers
Byte
0
1-5
Description
Pwd Default
Output frequency, hardware / I2C frequency
See individual byte
select, spread spectrum & output enable
description
control register.
Active / inactive output control registers.
See individual byte
description
Writing to this register will configure byte
count and how many byte will be read back.
06H
Do not write 00H to this byte.
Latched Inputs Read Back
The inverse of the latched inputs level could See individual byte
7
description
Register
be read back from this register.
Watchdog enable, watchdog status and
000,0000
Watchdog Control Registers
8 Bit[6:0] programmable 'safe' frequency' can be
configured in this register.
This bit select whether the output frequency
0
VCO Control Selection Bit
8 Bit[7] is control by hardware/byte 0 configurations
or byte 14&15 programming.
Writing to this register will configure the
FFH
Watchdog Timer Count Register
9
number of seconds for the watchdog timer
to reset.
This is an unused register. Writing to this
ICS Reserved Register
10
00H
register will not affect device functionality.
Byte 11 bit[3:0] is ICS vendor id - 0001.
Device ID, Vendor ID & Revision ID
See individual byte
11-12 Other bits in these 2 registers designate
description
Registers
device revision ID of this part.
Don't write into this register, writing 1's will
ICS Reserved Register
13
00H
cause malfunction.
These registers control the dividers ratio
Depended on
VCO Frequency Control Registers
14-15 into the phase detector and thus control the hardware/byte 0
configuration
VCO output frequency.
Byte Count Read Back Register
6
Spread Spectrum Control
Registers
16-17
Output Dividers Control Registers
18-20
Group Skews Control Registers
21
Output Rise/Fall Time Select
Registers
22
These registers control the spread
percentage amount.
Changing bits in these registers result in
frequency divider ratio changes. Incorrect
configuration of group output divider ratio
can cause system malfunction.
Increment or decrement the group skew
amount as compared to the initial skew.
These register will control the group rise
and fall time.
Depended on
hardware/byte 0
configuration
Depended on
hardware/byte 0
configuration
See individual byte
description
See individual byte
description
Notes:
1.
2.
3.
4.
5.
6.
7.
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 6.
When writing to byte 14 - 15, byte 16 - 17 and byte 18 - 20, 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.
4
ICS94203
Byte 0: Functionality and frequency select register (Default=0)
Bit
Bit2 Bit7 Bit6 Bit5 Bit4 VCO/REF
Divider
FS4 FS3 FS2 FS1 FS0
Bit
(2,7:4)
Bit 3
Bit 1
Bit 0
PWD
Description
VCO
MHz
VCO/ CPUCLK SDRAM
CPU
MHz
MHz
0
0
0
0
0
362/13
398.71
6
0
0
0
0
1
352/14
360.00
6
0
0
0
1
0
504/18
400.91
6
0
0
0
1
1
315/11
410.02
6
0
0
1
0
0
440/15
420.00
6
0
0
1
0
1
440/14
450.00
6
0
0
1
1
0
503/15
480.14
6
0
0
1
1
1
313/9
497.95
6
0
1
0
0
0
515/37
199.29
2
0
1
0
0
1
447/40
160.29
2
0
1
0
1
0
518/37
200.45
2
0
1
0
1
1
446/31
206.00
2
0
1
1
0
0
484/33
210.00
2
0
1
1
0
1
507/33
219.98
2
0
1
1
1
0
514/32
229.99
2
0
1
1
1
1
461/11
600.06
2
1
0
0
0
0
362/13
398.71
3
1
0
0
0
1
503/15
480.14
3
1
0
0
1
0
504/18
400.91
3
1
0
0
1
1
488/17
411.02
3
1
0
1
0
0
440/15
420.00
3
1
0
1
0
1
395/13
435.05
3
1
0
1
1
0
440/14
450.00
3
1
0
1
1
1
503/15
480.14
3
1
1
0
0
0
362/13
398.71
3
1
1
0
0
1
503/15
480.14
3
1
1
0
1
0
504/18
400.91
3
1
1
0
1
1
488/17
411.02
3
1
1
1
0
0
440/15
420.00
3
1
1
1
0
1
395/13
435.05
3
1
1
1
1
0
440/14
450.00
3
1
1
1
1
1
503/15
480.14
3
0-Frequency is selected by hardware select, latched inputs
1- Frequency is selected by Bit 2,7:4
0- Normal
1- Spread spectrum enable ± 0.35% Center Spread
0- Running
1- Tristate all outputs
66.45
60.00
66.80
68.33
70.00
75.00
80.00
83.00
99.65
80.00
100.23
103.00
105.00
110.00
115.00
200.00
132.86
160.00
133.64
137.00
140.00
145.00
150.00
160.00
132.90
160.00
133.64
137.00
140.00
145.00
150.00
160.00
99.65
90.00
100.20
102.50
105.00
112.50
120.00
124.50
99.65
80.00
100.23
103.00
105.00
110.00
115.00
200.00
132.86
160.00
133.64
137.00
140.00
145.00
150.00
160.00
99.65
100.00
100.23
102.75
105.00
108.75
112.50
120.00
3V66
MHz
PCICLK
MHz
IOAPIC
MHz
66.43
60.00
66.80
68.33
70.00
75.00
80.00
83.00
66.43
53.33
66.84
68.67
70.00
73.33
76.67
100.00
66.43
80.00
66.82
68.50
70.00
72.50
75.00
80.00
66.93
80.00
66.82
68.50
70.00
72.50
75.00
80.00
33.21
30.00
33.40
34.17
35.00
37.50
40.00
41.50
33.21
26.67
33.41
34.33
35.00
36.67
38.33
50.00
33.21
40.00
33.41
34.25
35.00
36.25
37.50
40.00
33.21
40.00
33.41
34.25
35.00
36.25
37.50
40.00
16.61
15.00
16.70
17.08
17.50
18.75
20.00
20.75
16.61
13.33
16.70
17.17
17.50
18.33
19.17
25.00
16.61
20.00
16.70
17.13
17.50
18.13
18.75
20.00
16.61
20.00
16.7
17.13
17.50
18.13
18.75
20.00
Notes:
1. Default at power-up will be for latched logic inputs to define frequency, as displayed by Bit 3.
5
Note 1
0
1
0
ICS94203
Byte 2: Output Control Register
(1 = enable, 0 = disable)
Byte 1: Output Control Register
(1 = enable, 0 = disable)
Bit
Bit 7
Bit 6
Bit 5
Bit 4
Bit 3
Bit 2
Bit 1
Bit 0
Pin#
27
28
37
PWD
1
1
1
1
1
1
1
1
Bit
Bit 7
Bit 6
Bit 5
Bit 4
Bit 3
Bit 2
Bit 1
Bit 0
Description
(Reserved)
(Reserved)
(Reserved)
24_48MHz
(Reserved)
48MHz
(Reserved)
SDRAM_F
Byte 3: Output Control Register
(1 = enable, 0 = disable)
Bit
Bit 7
Bit 6
Bit 5
Bit 4
Bit 3
Bit 2
Bit 1
Bit 0
Pin#
20
19
18
17
14
13
12
PWD
0
1
1
1
1
1
1
1
Pin#
31
32
33
34
PWD
1
1
1
1
1
1
1
1
PW D
1
1
1
1
1
1
1
1
Description
SDRAM7
SDRAM6
SDRAM5
SDRAM4
SDRAM3
SDRAM2
SDRAM1
SDRAM0
Byte 4: Output Control Register
(1 = enable, 0 = disable)
Description
Reserved
PCICLK6
PCICLK5
PCICLK4
PCICLK3
PCICLK2
PCICLK1
PCICLK0
Bit
Bit 7
Bit 6
Bit 5
Bit 4
Bit 3
Bit 2
Bit 1
Bit 0
Byte 5: Output Control Register
(1 = enable, 0 = disable)
Bit
Bit 7
Bit 6
Bit 5
Bit 4
Bit 3
Bit 2
Bit 1
Bit 0
Pin#
38
39
40
41
44
45
46
47
Pin#
9
7
8
56
54
50
51
PW D
1
1
1
1
1
X
1
1
Description
3V66_2
3V66_0
3V66_1
REF
IOAPIC0
Reserved
CPUCLK1
CPUCLK0
Byte 6: Byte Count Read Back Register
Bit
Bit 7
Bit 6
Bit 5
Bit 4
Bit 3
Bit 2
Bit 1
Bit 0
Description
(Reserved)
(Reserved)
(Reserved)
(Reserved)
SDRAM11
SDRAM10
SDRAM9
SDRAM8
Pin#
-
PW D
0
0
0
0
0
1
1
0
Description
R e s e r ve d ( N o t e )
R e s e r ve d ( N o t e )
R e s e r ve d ( N o t e )
R e s e r ve d ( N o t e )
R e s e r ve d ( N o t e )
R e s e r ve d ( N o t e )
R e s e r ve d ( N o t e )
R e s e r ve d ( N o t e )
Note: Writing to this register will configure byte count and
how many bytes will be read back, default is 6 bytes.
Notes:
1. Inactive means outputs are held LOW and are disabled from switching. These outputs are designed to be configured at
power-on and are not expected to be configured during the normal modes of operation.
2. PWD = Power on Default
6
ICS94203
Byte 7: Latch Inputs Readback Register
Bit
Bit 7
Bit 6
Bit 5
Bit 4
Bit 3
Bit 2
Bit 1
Bit 0
PWD
0
0
X
X
X
X
X
X
Byte 8: VCO Control Selection Bit &
Watchdog Timer Control Register
Bit
Bit 7
Bit 6
Bit 5
Bit 4
Bit 3
Bit 2
Bit 1
Bit 0
Description
(Reserved)
(Reserved)
(SEL24_48#)#
FS4#
FS3#
FS2#
FS1#
FS0#
PWD
0
0
0
0
0
0
0
0
Description
0=Hw/B0 freq / 1=B14&15 freq
WD Enable 0=disable / 1=enable
WD Status 0=normal / 1=alarm
WD Safe Frequency, FS4
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 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
1
1
1
Byte 10: ICS Reserved Register
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 the
watchdog timer will wait before it
goes to alarm mode and reset the
frequency to the safe setting. Default
at power up is 15 X 290ms = 4.4
seconds. Note, this timer does not
control the RESET# signal (pin 30)
in case of the frequency ratio change.
PWD
0
0
0
0
0
0
0
0
Description
(Reserved)
(Reserved)
(Reserved)
(Reserved)
(Reserved)
(Reserved)
(Reserved)
(Reserved)
Note: This is an unused register. Writing to this register will
not affect device performance or functionality.
Byte 11: Vender ID & Device ID Register
Bit
Bit 7
Bit 6
Bit 5
Bit 4
Bit 3
Bit 2
Bit 1
Bit 0
PWD
0
0
1
1
0
0
0
1
Byte 12: Revision ID Register
Bit
Bit 7
Bit 6
Bit 5
Bit 4
Bit 3
Bit 2
Bit 1
Bit 0
Description
Device ID
Device ID
Device ID
Device ID
Vendor ID
Vendor ID
Vendor ID
Vendor ID
Note: ICS Vendor ID is 0001 as in Number 1 in
frequency generation.
PWD
X
X
X
X
X
X
X
X
Description
Revision
Revision
Revision
Revision
Revision
Revision
Revision
Revision
ID
ID
ID
ID
ID
ID
ID
ID
Note: Device ID and Revision ID values will be based on
individual device and its revision.
Notes:
1. PWD = Power on Default
7
ICS94203
Byte 13: ICS Reserved Register
Bit
Bit 7
Bit 6
Bit 5
Bit 4
Bit 3
Bit 2
Bit 1
Bit 0
Byte 14: VCO Frequency Control Register
PWD
Description
0
(Reserved)
0
(Reserved)
0
(Reserved)
W0 timer base select
0
0=290ms
1=0.5ms
0
(Reserved)
0
(Reserved)
0
(Reserved)
0
(Reserved)
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
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
Note: The decimal representation of these 7 bits (Byte 14
[6:0]) + 2 is equal to the REF divider value .
Note: DON'T write a '1' into this register, it will
cause malfunction.
Byte 15: 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
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
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 15 bit
[7:0] & Byte 14 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 15 bit
& byte 14 bit 7.
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, 0111 (17H) to byte 6 for readback of 23 bytes (byte 0-22).
3. Read back byte 16-24 and copy values in these registers.
4. Re-initialize the write sequence.
5. Write a '1' to byte 8 bit 7 indicating you want to use byte 14 and 15 to control the VCO frequency.
6. Write to byte 14 & 15 with the desired VCO & REF divider values.
7. Write to byte 16 to 22 with the values you copy from step 3. This maintains the output divider mux controls the same gear ratio.
8. 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 14 and 15 unless the system is to reboot.
8
ICS94203
Note:
1. User needs to ensure step 3 & 7 is carried out. Systems with wrong spread percentage and/or group to group divider ratio
programmed into bytes 16-20 could be unstable. Step 3 & 7 assure the correct spread and gear ratio.
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. Users can also utilize software utility provided to program VCO frequency from ICS Application Engineering.
5. Spread percent needs to be calculated based on VCO frequency, spread modulation frequency and spreadamount desired. See
Application note for software support.
Byte 17: Spread Spectrum Control Register
Byte 16: 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
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
PWD
X
0
X
X
X
X
X
X
Description
Divider control Bit26
Divider control Bit25
Divider control Bit24
Spread Spectrum Bit12
Spread Spectrum Bit11
Spread Spectrum Bit10
Spread Spectrum Bit9
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 18: Output Dividers Control Register
Byte 19: Output Dividers 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
Description
Output Divider MUX Control Bit7
Output Divider MUX Control Bit6
Output Divider MUX Control Bit5
Output Divider MUX Control Bit4
Output Divider MUX Control Bit3
Output Divider MUX Control Bit2
Output Divider MUX Control Bit1
Output Divider MUX Control Bit0
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
Description
Output Divider MUX Control Bit15
Output Divider MUX Control Bit14
Output Divider MUX Control Bit13
Output Divider MUX Control Bit12
Output Divider MUX Control Bit11
Output Divider MUX Control Bit10
Output Divider MUX Control Bit9
Output Divider MUX Control Bit8
Note: Changing bits in these registers results in frequency
divider ratio changes. Incorrect configuration of
group gear ratio can cause system malfunction.
Note: Changing bits in these registers results in frequency
divider ratio changes. Incorrect configuration of
group gear ratio can cause system malfunction.
Notes:
1. PWD = Power on Default
2. The power on default for byte 16-20 depends on the harware (latch inputs FS[0:4]) or IIC (Byte 0 bit [1:7]) setting. Be sure to read
back and re-write the values of these 5 registers when VCO frequency change is desired for the first pass.
9
ICS94203
Byte 20: Output Dividers 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 21: ICS Reserved Register
Description
Output Divider MUX Control Bit23
Output Divider MUX Control Bit22
Output Divider MUX Control Bit21
Output Divider MUX Control Bit20
Output Divider MUX Control Bit19
Output Divider MUX Control Bit18
Output Divider MUX Control Bit17
Output Divider MUX Control Bit16
Bit
Bit 7
Bit 6
Bit 5
Bit 4
Bit 3
Bit 2
Bit 1
Bit 0
Note: Changing bits in these registers results in
frequency divider ratio changes. Incorrect
configuration of group gear ratio can cause
system malfunction.
PWD
1
0
1
1
0
1
1
0
Description
3V66 to PCI Skew Bit3
3V66 to PCI Skew Bit2
3V66 to PCI Skew Bit1
3V66 to PCI Skew Bit0
3V66 to IOAPIC Skew Bit 3
3V66 to IOAPIC Skew Bit 2
3V66 to IOAPIC Skew Bit 1
3V66 to IOAPIC Skew Bit 0
Note: Each increment or decrement of bit 4 to 7 will introduce
100ps delay or advance on all of the above clocks.
Byte 22: Output Rise/Fall Time Select Register
Bit
Bit 7
Bit 6
Bit 5
Bit 4
Bit 3
Bit 2
Bit 1
Bit 0
PWD
0
0
0
0
0
0
0
0
Description
24,48MHz 0=Normal, 1=Weak
IOAPIC/REF 0=Normal, 1=Weak
PCI 0=Normal, 1=Weak
SDRAM_F 0=Normal, 1=Weak
SDRAM [0:11] 0=Normal, 1=Weak
3V66 0=Normal, 1=Weak
CPU1 0=Normal, 1=Weak
CPU0 0=Normal, 1=Weak
Notes:
1. PWD = Power on Default
2. The power on default for byte 16-20 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 5 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 21-22 will lose their default power up value.
Notes:
1. PWD = Power on Default
10
ICS94203
Absolute Maximum Ratings
Core Supply Voltage . . . . . . . . . . . . . . . . . . . . . . . .
I/O Supply Voltage . . . . . . . . . . . . . . . . . . . . . . . . .
Logic Inputs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Ambient Operating Temperature . . . . . . . . . . . . . .
Storage Temperature . . . . . . . . . . . . . . . . . . . . . . . .
Case Temperature . . . . . . . . . . . . . . . . . . . . . . . . . .
4.6 V
3.6V
GND –0.5 V to VDD +0.5 V
0°C to +70°C
–65°C to +150°C
115°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.
Group Timing Relationship Table1
Group
CPU 66MHz
SDRAM 100MHz
CPU 100MHz
SDRAM 100MHz
CPU 133MHz
SDRAM 100MHz
CPU 133MHz
SDRAM 133MHz
Offset
Tolerance
Offset
Tolerance
Offset
Tolerance
Offset
Tolerance
CPU to SDRAM
2.5ns
500ps
5.0ns
500ps
0.0ns
500ps
3.75ns
500ps
CPU to 3V66
7.5ns
500ps
5.0ns
500ps
0.0ns
500ps
0.0ns
500ps
SDRAM to 3V66
0.0ns
500ps
0.0ns
500ps
0.0ns
500ps
3.75ns
500ps
3V66 to PCI
1.5-3.5ns
500ps
1.5-3.5ns
500ps
1.5-3.5ns
500ps
1.5 -3.5ns
500ps
PCI to PCI
USB & DOT
0.0ns
Asynch
1.0ns
N/A
0.0ns
Asynch
1.0ns
N/A
0.0ns
Asynch
1.0ns
N/A
0.0ns
Asynch
1.0ns
N/A
Electrical Characteristics - Input/Supply/Common Output Parameters
TA = 0 - 70º C; Supply Volt age VDD = 3.3 V +/-5% (unless otherwise stated)
PARAMETER
SYMBOL
CONDITIONS
MIN TYP
MAX UNITS
2
VDD+0.3
V
Input High Voltage
VIH
VSS-0.3
0.8
V
Input Low Voltage
VIL
Input High Current
IIH
VIN = VDD
5
A
Input Low Current
IIL1
VIN=0 V;Inputs with no pull-up resistors
-5
uA
Input Low Current
IIL2
VIN=0 V; Inputs with pull-up resistors
-200
uA
Supply Current
IDD3.3OP100
CL=30 pF
346
400
mA
Power Down
PD
4.3
600
mA
12 14.318
16
MHz
Input frequency
Fi
VDD = 3.3 V;
CIN
Logic Inputs
5
pF
Logic Inputs
5
pF
Input Capacitance1
CIN
CINX
X1 & X2 pins
27
45
pF
Clk Stabilization1
TSTAB
From VDD= 3.3 V to 1% target Freq.
3
ms
1
Guaranteed by design, not 100% tested in production.
11
ICS94203
Electrical Characteristics - CPU
TA = 0 - 70C; VDDL = 2.5 V +/-5%; CL = 10-20 pF (unless otherwise specified)
PARAMETER
SYMBOL
CONDITIONS
1
RDSP2B
VO = VDD*(0.5)
Output Impedance
1
R
VO = VDD*(0.5)
Output Impedance
DSN2B
VOH2B
IOH = -1 mA
Output High Voltage
IOL = 1 mA
VOL2B
Output Low Voltage
VOH @ MIN = 1.0 V
IOH2B
Output High Current
VOH @ MAX = 2.375 V
VOL @ MIN = 1.2 V
IOL2B
Output Low Current
VOL @ MAX = 0.3 V
1
tr2B
VOL = 0.4 V, VOH = 2.0 V
Rise Time
1
Fall Time
1
Duty Cycle
1
Skew window
1
Jitter, Cycle-to-cycle
1
MIN
13.5
13.5
2
0.4
TYP
20
27
2.5
0.18
-51
-11
41
15
1
1
-27
27
MAX UNITS
45
Ω
45
Ω
V
0.4
V
-27
mA
30
1.6
mA
ns
tf2B
VOH = 2.0 V, VOL = 0.4 V
0.4
dt2B
VT = 1.25 V
45
49
55
%
tsk2B
VT = 1.25 V
40
175
ps
VT = 1.25 V, CPU=66 MHz
245
250
VT = 1.25 V, CPU=100 MHz
160
250
VT = 1.25 V, CPU=133 MHz
290
250
tjcyc-cyc
1.6
ns
ps
Guaranteed by design, not 100% tested in production.
Electrical Characteristics - 3V66
TA = 0 - 70C; VDD = 3.3 V +/-5%; CL = 10-20 pF (unless otherwise specified)
PARAMETER
SYMBOL
CONDITIONS
1
Output Impedance
RDSP1B
VO = VDD*(0.5)
1
VO = VDD*(0.5)
Output Impedance
RDSN1B
IOH = -1 mA
Output High Voltage
VOH1
IOL = 1 mA
Output Low Voltage
VOL1
VOH @ MIN = 1.0 V
IOH1
Output High Current
VOH @ MAX = 3.135 V
VOL @ MIN = 1.95 V
IOL1
Output Low Current
VOL @ MAX = 0.4 V
Rise Time1
1
Fall Time
1
Duty Cycle
Skew window1
Jitter, Cycle-to-cycle1
1
MIN
12
12
2.4
-27
29
TYP
17.4
22.4
3.3
0.009
-68
-14
77
24
MAX UNITS
Ω
55
Ω
55
V
0.55
V
-29
mA
27
mA
tr1
VOL = 0.4 V, VOH = 2.4 V
0.5
1.4
2
ns
tf1
dt1
VOH = 2.4 V, VOL = 0.4 V
0.5
1.7
2
ns
VT = 1.5 V
45
49
55
%
tsk1
VT = 1.5 V
35
175
ps
tjcyc-cyc1
VT = 1.5 V
292
500
ps
Guaranteed by design, not 100% tested in production.
12
ICS94203
Electrical Characteristics - IOAPIC
TA = 0 - 70C; VDDL = 2.5 V +/-5%; CL = 10-20 pF (unless otherwise specified)
CONDITIONS
PARAMETER
SYMBOL
1
Output Impedance
RDSP4B
VO = VDD*(0.5)
1
VO = VDD*(0.5)
Output Impedance
RDSN4B
Output High Voltage
VOH4B
IOH = -1 mA
IOL = 1 mA
Output Low Voltage
VOL4B
VOH @ MIN = 1.0 V
IOH4B
Output High Current
VOH @ MAX = 2.375 V
VOL @ MIN = 1.2 V
IOL4B
Output Low Current
VOL @ MAX = 0.3 V
Rise Time1
1
Fall Time
Duty Cycle1
Jitter, Cycle-to-cycle1
1
tr4B
tf4B
dt4B
tjcyc-cyc4B
MIN
9
9
2
-27
27
TYP
28
28
2.4
0.25
-62
-12
35
8
MAX UNITS
30
Ω
30
Ω
V
0.4
V
-27
mA
30
mA
VOL = 0.4 V, VOH = 2.0 V
VOH = 2.0 V, VOL = 0.4 V
0.4
0.4
1.45
0.97
1.6
1.6
ns
ns
VT = 1.25 V
45
49.3
55
%
130
500
ps
VT = 1.25 V
Guaranteed by design, not 100% tested in production.
Electrical Characteristics - SDRAM
TA = 0 - 70C; VDD = 3.3 V +/-5%; CL = 20-30 pF (unless otherwise specified)
PARAMETER
SYMBOL
CONDITIONS
1
VO = VDD*(0.5)
Output Impedance
RDSP3B
VO = VDD*(0.5)
Output Impedance
RDSN3B1
Output High Voltage
VOH3
IOH = -1 mA
Output Low Voltage
VOL3
IOL = 1 mA
VOH @ MIN = 2.0 V
IOH3
Output High Current
VOH @ MAX = 3.135 V
VOL @ MIN = 1.0 V
IOL3
Output Low Current
VOL @ MAX = 0.4 V
Rise Time
Fall Time
1
1
1
Duty Cycle
Skew window1
Jitter, Cycle-to-cycle
1
1
MIN
10
10
2.4
-54
54
TYP
16
17.5
3.3
0.01
-70
-29
90
28
MAX UNITS
24
Ω
24
Ω
V
0.4
V
-46
mA
53
mA
tr3
VOL = 0.4 V, VOH = 2.4 V
0.4
0.9
1.6
ns
tf3
dt3
VOH = 2.4 V, VOL = 0.4 V
0.4
0.8
1.6
ns
VT = 1.5 V
45
49.2
55
%
VT = 1.5 V
83
250
ps
VT = 1.5 V, CPU=66,100,133 MHz
214
250
ps
tsk3
tjcyc-cyc3
Guaranteed by design, not 100% tested in production.
13
ICS94203
Electrical Characteristics - PCI
TA = 0 - 70C; VDD = 3.3 V +/-5%; CL = 10-30 pF (unless otherwise specified)
PARAMETER
SYMBOL
CONDITIONS
1
Output Impedance
RDSP1B
VO = VDD*(0.5)
1
VO = VDD*(0.5)
Output Impedance
RDSN1B
IOH = -1 mA
Output High Voltage
VOH1
IOL = 1 mA
Output Low Voltage
VOL1
VOH @ MIN = 1.0 V
IOH1
Output High Current
VOH @ MAX = 3.135 V
VOL @ MIN = 1.95 V
IOL1
Output Low Current
VOL @ MAX = 0.4 V
Rise Time1
1
Fall Time
1
Duty Cycle
Skew window1
Jitter, Cycle-to-cycle1
1
MIN
12
12
2.4
-27
29
TYP
17.4
22.4
3.3
0.009
-67
-14
77
24
MAX UNITS
Ω
55
Ω
55
V
0.55
V
-29
mA
27
mA
tr1
VOL = 0.4 V, VOH = 2.4 V
0.5
1.7
2.5
ns
tf1
dt1
VOH = 2.4 V, VOL = 0.4 V
0.5
1.9
2.5
ns
VT = 1.5 V
45
51
55
%
tsk1
VT = 1.5 V
213
500
ps
tjcyc-cyc1
VT = 1.5 V
285
500
ps
Guaranteed by design, not 100% tested in production.
Electrical Characteristics - REF, 48MHz
TA = 0 - 70C; VDD = 3.3 V +/-5%; CL = 10-20 pF (unless otherwise specified)
PARAMETER
SYMBOL
CONDITIONS
1
Output Impedance
RDSP5B
VO = VDD*(0.5)
Output Impedance
RDSN5B1
VO = VDD*(0.5)
Output High Voltage
VOH15
IOH = -1 mA
IOL = 1 mA
Output Low Voltage
VOL5
VOH @ MIN = 1.0 V
IOH5
Output High Current
VOH @ MAX = 3.135 V
VOL @ MIN = 1.95 V
IOL5
Output Low Current
VOL @ MAX = 0.4 V
1
Rise Time
1
Fall Time
1
Duty Cycle
MIN
15
15
2.4
27
TYP
18
18.75
3.27
0.025
-76
-12
71
22
-33
MAX UNITS
60
Ω
60
Ω
V
0.4
V
-33
mA
29
mA
tr5
VOL = 0.4 V, VOH = 2.4 V
0.4
1
4
ns
tf5
dt5
VOH = 2.4 V, VOL = 0.4 V
VT = 1.5 V
0.4
1.7
4
ns
45
54.1
55
%
1
Guaranteed by design, not 100% tested in production.
14
ICS94203
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 ICS94203
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 5bit 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 Via to Gnd
Device
Pad
8.2K Clock trace to load
Series Term. Res.
Fig. 1
15
ICS94203
Power Down Waveform
Note
1. After PD# is sampled active (Low) for 2 consective rising edges of CPUCLKs, all the
output clocks are driven Low on their next High to Low tranistiion.
2. Power-up latency <3ms.
3. Waveform shown for 100MHz
16
ICS94203
0ns
10ns
20ns
30ns
Cycle Repeats
CPU 66MHz
CPU 100MHz
CPU 133MHz
SDRAM 100MHz
SDRAM 133MHz
3.5V 66MHz
PCI 33MHz
APIC 33MHz
REF 14.318MHz
USB 48MHz
Group Offset Waveforms
17
40ns
ICS94203
SYMBOL
In Millimeters
COMMON DIMENSIONS
MIN
MAX
In Inches
COMMON DIMENSIONS
MIN
MAX
A
2.413
2.794
.095
.110
A1
0.203
0.406
.008
.016
b
0.203
0.343
.008
.0135
c
D
0.127
0.254
SEE VARIATIONS
.005
.010
SEE VARIATIONS
E
10.033
10.668
.395
.420
E1
7.391
7.595
.291
.299
e
0.635 BASIC
h
0.381
L
0.508
1.016
SEE VARIATIONS
N
α
0.635
0°
0.025 BASIC
.015
.025
.020
.040
SEE VARIATIONS
8°
0°
8°
MAX
MIN
MAX
VARIATIONS
N
D mm.
MIN
D (inch)
28
9.398
9.652
.370
.380
34
11.303
11.557
.445
.455
48
15.748
16.002
.620
.630
56
18.288
18.542
.720
.730
64
20.828
21.082
.820
.830
Ordering Information
ICS94203yF-T
Example:
ICS XXXX y F - T
Designation for tape and reel packaging
Package Type
F=SSOP
Revision Designator (will not correlate with datasheet revision)
Device Type
Prefix
ICS, AV = Standard Device
18
ICS reserves the right to make changes in the device data identified in
this publication without further notice. ICS advises its customers to
obtain the latest version of all device data to verify that any
information being relied upon by the customer is current and accurate.