ICS9248-162 Datasheet, PDF (1/16 Pages) Integrated Circuit Systems – Frequency Generator & Integrated Buffers for PENTIUM/ProTM & K6

Integrated
Circuit
Systems, Inc.
ICS9248 - 162
Frequency Generator & Integrated Buffers for PENTIUM/Pro^TM & K6
General Description
The ICS9248-162 is the single chip clock solution for various
mobile chipset platforms. It provides all necessary clock signals
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 ICS9248-162
employs a proprietary closed loop design, which tightly
controls the percentage of spreading over process and
temperature variations.
Block Diagram
Features
• Up to 137MHz frequency support
• Spread Spectrum for EMI control
• Serial I²C interface for Power Management,
Frequency Select, Spread Spectrum.
• Provides the following system clocks
- 4-CPUs @ 2.5/3.3V, up to 137MHz.
(including CPUCLK_F)
- 9-SDRAMs @3.3V, up to 137MHz
(including SDRAM_F)
- 8-PCI @3.3V, CPU/2 or CPU/3
(including 1 free running PCICLK_F)
- 1-24/48MHz @3.3V
- 1-48MHz @3.3V fixed
- 2-REF @3.3V, 14.318MHz.
• Efficient Power management scheme through PCI
and CLK STOP CLOCKS
• Spread Spectrum ± .25%, & 0 to -0.5% down spread
X1
X2
BUFFER IN
FS(3:0)
SEL24_48#
CLK_STOP#
PCI_STOP#
CPU2.5_3.3#
SDATA
SCLK
PD#
PLL2
/2
XTAL
OSC
PLL1
Spread
Spectrum
LATCH
POR
Control
Logic
Config.
Reg.
STOP
STOP
PCI
CLOCK
DIVDER
STOP
Pin Configuration
48MHz
24_48MHz
VDDREF
1
REF0
2
2 ^REF(1:0)
GNDREF
3
X1
4
X2
5
VDDPCI
6
*CPU2.5_3.3#/PCICLK_F
7
CPUCLK_F
*FS3/PCICLK0
8
GNDPCI
9
3 ^{CPUCLK (2:0)}
*SEL24_48#/PCICLK1
10
PCICLK2
11
8 ^{SDRAM (7:0)}
PCICLK3
12
PCICLK4
13
SDRAM_F
VDDPCI
14
BUFFER IN
15
GNDPCI
16
PCICLK (6:0)
7
PCICLK5
17
PCICLK6
18
PCICLK_F
VDDCOR
19
PCI_STOP#
20
*PD#
21
GND48
22
SDATA
23
SCLK
24
48
REF1/FS2*
47
VDDLCPU
46
CPUCLK_F
45
CPUCLK0
44
GNDLCPU
43
CPUCLK1
42
CPUCLK2
41
CLK_STOP#
40
GNDSDR
39
SDRAM_F
38
SDRAM0
37
SDRAM1
36
VDDSDR
35
SDRAM2
34
SDRAM3
33
GNDSDR
32
SDRAM4
31
SDRAM5
30
VDDSDR
29
SDRAM6
28
SDRAM7
27
VDD48
26
48MHz/FS0*
25
24_48MHz/FS1*
Power Groups
VDDLCPU, GNDLCPU = CPUCLK [2:0], CPUCLK_F
VDDSDR, GNDSDR = SDRAMCLKS [7:0], SDRAM_F
VDDPCI, GNDPCI = PCICLKS [6:0], PCICLK_F
VDD48, GND48 = 48MHz, 24MHz
VDDREF, GNDREF = REF, X1, X2
VDDCOR = PLL CORE
9248-162 Rev A 8/31/00
48-Pin SSOP and TSSOP
* Internal Pull-up Resistor of 120K to VDD
Pentium is a trademark of Intel Corporation
I²C is a trademark of Philips Corporation
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.