9
Intel® Xeon™ Processor with 512 KB L2 Cache System Compatibility Guidelines
PWRGOOD input to the processor. PWR_OK will be deasserted when any output of an
ATX12V-compliant or SSI-compliant power supply falls below regulation limits. It is
important to maintain SM_VCC at any time the output of the VRM is enabled. Driving the
VRM’s OUTEN with the PWR_OK signal will ensure correct sequencing at both power up
and power down.
Figure 1. Voltage Sequence Timing Requirements
VRM
Power
Supply
Processor
VID[4:0]
3.3 VDC
PWR_OK
OUTEN
PWRGD
PWRGOOD
SM_VCC
3.3 VDC/SM_VCC
PWROK
OUTEN
Power Down
3.3 VDC/SM_VCC
PWR_OK /
VID_OUT
OUTEN
VRM
PWRGD
Processor
PWRGOOD
Processor
RESET
T
0
= 95% 3.3 volt level
Power Up
SM_VCC out of
regulation
T
0
+10mS
> valid p/s voltages + 100 ms
Power Down Warning > 1ms
1ms < T
36
<10ms
System
PWRGD
Logic
...
...
VID
VID