ICS9248-64
ICS9248-64 is Frequency Generator & Integrated Buffers manufactured by Integrated Circuit Systems.
Integrated Circuit Systems, Inc.
AMD-K7TM System Clock Chip
General Description
The ICS9248-64 is a main clock synthesizer chip for AMDK7 based systems. This provides all clocks required for such a system when used with a Zero Delay Buffer Chip such as the ICS9179-06. Spread Spectrum may be enabled by driving the SPREAD# pin active. Spread spectrum typically reduces system EMI by 8d B to 10d B. This simplifies EMI qualification without resorting to board design iterations or costly shielding. The ICS9248-64 employs a proprietary closed loop design, which tightly controls the percentage of spreading over process and temperature variations.
Features
- Generates the following system clocks:
- 3 differential pair open drain CPU clocks (1.5V external pull-up; up to 133MHz).
- 8 PCI including 1 free running (3.3V) @33.3MHz.
- 2 AGP(3.3V) up to 66.6MHz.
- 2 REF(3.3V)@14.318MHz
- 1 48MHz(3.3V)
- 24 / 48MHz(3.3V) Skew characteristics:
- CPU -CPU<250ps
- CPUt
- CPUc <200ps (differential pair)
- PCI
- PCI: <500ps
- CPU
- SDRAM_OUT: < 250ps
- CPU
- AGP <500ps Efficient Power Management through PD#, PCI_STOP# and CPU_STOP#. Spread Spectrum option for EMI reduction (-1.0% down spread). Uses external 14.318 MHz crystal
- -
- Block Diagram
- Pin Configuration
- 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 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 48 47 46 45 44 43 42 41 40 39 38 37 36 35 34 33 32 31 30 29 28 27 26 25 VDDREF GNDSD SDRAM_OUT VDDSD RESERVED CPUCLKC2 CPUCLKT2 GNDCPU CUCLKC1 CPUCLKT1 GND CPUCLKC0 CPUCLKT0 RESERVED VDD GND PCI_STOP# CPU_STOP# PD# SPREAD# TEST# SDATA 2 I C SCLK GND48
{
48-Pin SSOP
- Internal 120K pullup resistor on indicated inputs
AMD-K is a trademark of Advanced Micro Devices. 9248-64 Rev C...
