Filter
Top Products
Chapter 3. 8260 Fault Tolerant Controller Module
The 8260 Fault Tolerant controller module is a critical component of the 8260.
One active controller module is always required in order to keep the 8260 hub
operational and running. Unlike the 8250 controller module, the 8260 Fault
Tolerant Controller module does not occupy any of the payload slots because it
resides on either slot 18 and/or 19 in the hub which are reserved for the
controller modules. This chapter provides you with detailed information about
the 8260 Fault Tolerant Controller module.
3.1 8260 Fault Tolerant Controller Module Overview
The controller module is an essential component of the 8260 and provides the
following functions:
•
Clock generating and its distribution across Enhanced TriChannel and
ShuntBus
This provides the clocking to the backplane and synchronizes the operation
of all the installed modules.
•
Monitoring the hub temperature and taking appropriate action in overheated
conditions
When the hub temperature rises in a particular area, the overheated
condition is signaled to the controller module. Then, the controller module
may power down 8260 modules within that area according to the power
classes assigned to the modules. This will be done to bring down the
temperature of the hub to an acceptable limit.
•
Inventory and intelligent power management
Each 8260 module has a serial EEPROM which is used for power
management and inventory purposes. The EEPROM is programmed at
manufacturing and includes information about how much power the module
requires, its serial number, model number, the vendor ID, and its hardware
revision level. Upon insertion into the hub, the 8260 modules will send Vital
Product Data (VPD) and their power requirements over the control bus (SCI)
to the controller module.
The controller module also has knowledge of how many power supplies are
installed in the hub and how much of the power is used by the currently
installed modules; therefore, it is able to determine if there is enough power
left in the hub to power up the new module. If the answer is yes, the
controller module will apply full power to the module allowing it to operate
normally. The controller module will also update its internal power tables to
take into account the power consumption of the new module. Finally, the
controller module informs the DMM of the VPD of the newly inserted module.
Via the DMM command, you can also display information about the power
supplies installed and the amount of power used by the existing modules.
More details about the intelligent power subsystem and the role the
controller module plays in managing the power for the hub is found in
Chapter 5, “8260 Intelligent Power Management Subsystem” on page 73.
Copyright IBM Corp. 1995 29