Compaq AlphaServer ES40 - System Power Controller (SPC)

1-22 Compaq AlphaServer ES40 Service Guide
1.10.1 System Power Controller (SPC)
The System Power Controller (SPC) is responsible for sequencing the
turn-on/turn-off of all power supplies and regulators, monitoring all
system power supplies and regulators, generating hardware resets to
all logic elements, and generating power system status signals for use
by other functional units within the system. Additionally, it is
responsible for emergency shutdown if the internal system
temperature exceeds permissible limits.
An 8-bit CMOS microprocessor (PIC 17C44) with associated programming
controls the functions of the SPC. The PIC processor receives inputs from:
•
Operator control panel (power-on, reset)
•
Power supplies and DC/DC regulators (Power-OK)
•
Thermal sensors (temperature failure)
•
TIG chip (command bus from the firmware)
•
Remote management console logic ( remote power up/down, reset)
It provides outputs to:
•
Power supplies and DC/DC regulators (power supply enables)
•
Processors (DC_OK, reset)
•
TIG bus chip (handshake)
•
Remote management console (power status)