ICS950401 Datasheet, PDF (3/14 Pages) Integrated Circuit Systems – AMD - K8TM System Clock Chip

ICS950401
General Description
The ICS950401 is a main clock synthesizer chip for AMD-K8. This provides all clocks required for Clawhammer and
Sledgehammer systems.
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 ICS950401
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.
Power Groups
VDDA = PLL2
VDDA = VDD for Core PLL
VDDREF = REF, Xtal
Pin 32
Pin 43
Pin 2
Skew Characteristics
Parameter
T_{sk_CPU_CPU}
T_{sk_CPU_PCI}
T_{sk_PCI_PCI}
T_{sk_PCI33-HT66}
T_{sk_CPU_HT66}
T_{sk_CPU_HT66}
T_{sk_CPU_CPU}
T_{sk_CPU_PCI}
T_{sk_PCI_PCI}
T_{sk_PCI33-HT66}
T_{sk_CPU_HT66}
T_{sk_CPU_HT66}
Description
Test Conditons
time independent
skew
not dependent on
V, T changes
time variant skew
varies over
V, T changes
measured at x-ing of CPU,
measured at x-ing of CPU,
1.5V of PCI clock
measured between rising
edge at 1.5V
measured between rising
edge at 1.5V
measured between rising
edge at 1.5V
measured at x-ing of CPU,
1.5V of PCI clock
measured at x-ing of CPU,
measured at x-ing of CPU,
1.5V of PCI clock
measured between rising
edge at 1.5V
measured between rising
edge at 1.5V
measured between rising
edge at 1.5V
measured at x-ing of CPU,
1.5V of PCI clock
Skew
Window
250
2000
500
500
2000
500
200
200
200
200
200
200
Unit
ps
ps
ps
ps
ps
ps
ps
ps
ps
ps
ps
ps
0499C—11/01/04
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