CDC921 Datasheet, PDF (15/17 Pages) Texas Instruments – 133-MHz CLOCK SYNTHESIZER/DRIVER FOR PC MOTHERBOARDS WITH 3-STATE OUTPUTS

CDC921
133-MHz CLOCK SYNTHESIZER/DRIVER FOR PC MOTHERBOARDS
WITH 3-STATE OUTPUTS
SCAS623 –MAY 27, 1999
PARAMETER MEASUREMENT INFORMATION
CPUx or PCIx Clock
CPUx or PCIx Clock
tsk(o)
tc
t(low)
t(high)
VT_REF
VT_REF
Ť Ť + t_sk(p) t_PLH–t_PHL
+ Duty Cycle
t_(low)
t_c
100
3V66 or CPUx
VT_REF
3V66, PCIx, or APIC
VT_REF
t(off) [3V66 to PCIx]
t(off) [CPUx to APIC]
t(off) [CPUx to 3V66]
Figure 4. Waveforms for Calculation of Skew, Offset, and Jitter
CPU
(internal)
PCI
(internal)
PWR_DWN
CPU
(external)
PCI
(external)
CRYSVTCAOL_{ÇÇÇÇÇÇÇÇÇÇÇÇÇÇÇÇÇÇÇÇÇÇÇÇÇÇÇÇÇÇÇÇÇ}
ÇÇÇÇÇÇÇÇÇÇÇÇÇÇÇÇÇÇÇÇÇÇÇÇÇÇÇÇÇÇÇÇÇÇ
NOTE A: Shaded sections on the VCO and Crystal waveforms indicate that the VCO and crystal oscillators are active and there is a valid clock.
Figure 5. Power-Down Timing
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