Frequency Generator & Integrated Buffers for Celeron & PII/III™
Recommended Application:
810/810E style chipset
Output Features:
•2- CPUs @2.5V @ 150MHz (up to 200MHz. achievable
through I
•9 - SDRAM @ 3.3V @ 150MHz (up to 200MHz.
achievable through I
2
C)
2
C)
•8 - PCICLK @ 3.3V
•1 - IOAPIC @ 2.5V,
•2 - 3V66MHz @ 3.3V
•2- 48MHz, @ 3.3V fixed.
•1- 24/48MHz, @ 3.3V
•1- REF @3.3V, 14.318MHz.
Features:
•Up to 200.4MHz frequency support
•Support FS0-FS3 trapping status bit for I
•Support power management: Power down Mode form I
2
C read back.
2
programming.
•Spread spectrum for EMI control ( ± 0.25% center).
•FS0, FS1, FS2, FS3 must have a internal 120K pull-Down
to GND.
•Uses external 14.318MHz crystal
Skew Specifications:
•CPU – CPU: <175ps
•SDRAM - SDRAM: < 250ps
•3V66 – 3V66: <175ps
•PCI – PCI: <500ps
•For group skew specifications, please refer to group
timing relationship table.
Pin Configuration
C
48-Pin 300mil SSOP
* These inputs have a 120K pull down to GND.
1 These are double strength.
Block Diagram
9248- 99 Rev A 8/27/99
Third party brands and names are the property of their respective owners.
Functionality
3SF2SF1SF0SF
0000
0001
0010
0011
0100
0101
0110
0111
100 0
100 1
1010
1011
1100
110 1
1110
1111
PRODUCT PREVIEW documents contain information on new
products in the sampling or preproduction phase of development.
Characteristic data and other specifications are subject to change
without notice.
UPC
MARDS
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33.5700.31133.5776.7338.8176.73
00.52100.52133.3876.1438.0276.14
00.92100.92100.6800.3405.1200.34
92.05100.31133.5776.7338.8176.73
00.05100.05100.00100.0500.5200.05
00.21100.21176.4733.7376.8133.73
00.54100.54176.6933.8471.4233.84
46.34100.80100.2700.6300.8100.63
03.8605.20133.8671.4380.7171.43
00.50100.50100.0700.5305.7100.53
00.83100.83100.2900.6400.3200.64
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76.6600.00176.6633.3376.6133.33
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06.33106.33170.9835.4472.2235.44
33.33100.00176.6633.3376.6133.33
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ICS9248-99
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Preliminary Product Preview
General Description
The ICS9248-99 is the single chip clock solution for Desktop
designs using 810/810/E style chipset. It provides all necessary
clock signals for such a system.
Spread spectrum may be enabled through I
Spread spectrum typically reduces system EMI by 8dB to
10dB. This simplifies EMI qualification without resorting to
board design iterations or costly shielding. The ICS9248-99
25SDATAINData input for I2C serial input, 5V tolerant input
28SCLKINClock input of I2C input, 5V tolerant input
29PD#IN
31, 32, 33, 35, 36,
37, 39, 40, 41
43GNDLCPUPWRGround pin for the CPU clocks.
44, 45CPUCLK [1:0]OUTCPU clock outputs.
46VDDLCPUPWRPower pin for the CPUCLKs. 2.5V
47IOAPICOUT2.5V clock output.
48VDDLAPICPWRPower pin for the IOAPIC. 2.5V
REF1OU T14.318 MHz reference clock.
FS3INFrequency select pin.
VDDPWR
GNDPWRGround pin for 3V outputs.
FS0INFrequency select pin.
PCICLK0OUTPCI clock output.
FS1INFrequency select pin.
PCICLK1OUTPCI clock output.
FS2INFrequency select pin.
PCICLK2OUTPCI clock output.
SEL24_48#IN
24_48MHzOUTClock output for super I/O/US B
SDRAM [8:0]OUTSDRAM clock outputs
3.3V Power s upply for SD RAM output buffers, PCI output buffers,
reference out
Select pin for enabling 24MHz or 48MHz
H=24MHz L=48MHz
Asynchronous active low input pin used to power down the device into a low
power state. The internal clocks are disabled and the VC O and the crystal are
ed. The latency of the power down will not be greater than 3ms.
sto
ut buffers and 48MHz output
Third party brands and names are the property of their respective owners.
2
Preliminary Product Preview
K
0
2
3
5
K
K
K
K
K
K
K
K
General I2C serial interface information
The information in this section assumes familiarity with I2C programming.
For more information, contact ICS for an I
2
C programming application note.
ICS92 48-99
How to Write:
Controller (host) sends a start bit.
Controller (host) sends the write address D2
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 5
ICS clock will acknowledge each byte one at a time.
Controller (host) sends a Stop bit
How to Write:
Controller (Host)ICS (Slave/Receiver)
Start Bit
Address
D2
(H)
Dummy Command Code
Dummy Byte Count
Byte 0
Byte 1
Byte 2
Byte 3
Byte 4
Byte 5
Stop Bit
(H)
AC
AC
AC
AC
ACK
AC
AC
AC
AC
How to Read:
Controller (host) will send start bit.
Controller (host) sends the read address D3
ICS clock will acknowledge
ICS clock will send the byte count
Controller (host) acknowledges
ICS clock sends first byte (Byte 0) through byte 5
Controller (host) will need to acknowledge each byte
Controller (host) will send a stop bit
How to Read:
Controller (Host)ICS (Slave/Receiver)
Start Bit
Address
D3
(H)
ACK
ACK
ACK
ACK
ACK
ACK
ACK
Stop Bit
AC
Byte Count
Byte
Byte 1
Byte
Byte
Byte 4
Byte
(H)
Notes:
1.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.
2.The data transfer rate supported by this clock generator is 100K bits/sec or less (standard mode)
3.The input is operating at 3.3V logic levels.
4.The data byte format is 8 bit bytes.
5.To simplify the clock generator I
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.
6.At power-on, all registers are set to a default condition, as shown.
Third party brands and names are the property of their respective owners.
2
C interface, the protocol is set to use only "Block-Writes" from the controller. The
3
ICS9248-99
Preliminary Product Preview
Serial Configuration Command Bitmap
Byte4: Functionality and Frequency Select Register (default = 0)