The backplane has two slots for power supply modules. The power supply connector for each
slot has a 1-bit slot address to identify the slot. The address bit for power supply slot 0 is grounded.
The address bit for slot 1 floats on the backplane. The power supply module provides a pull-up
resistor on the address line on slot 1. The power supply module uses the slot address bit as bit
A0 for generating a unique I2C address for the FRU ID prom. Figures 1-7 and 1-8 identify and
show the location of the backplane power supply modules.
Figure 1-7 Backplane Power Supply Module
Each power supply slot has a power supply detect bit that determines if the power supply module
is inserted into the backplane slot. This bit is routed to an input on the RPMs. The RPM provides
a pull-up resistor for logic 1 when the power supply module is missing. When the power supply
module is inserted into the slot, the bit is grounded by the power supply and logic 0 is detected
by the RPM, indicating that the power supply module is present in the backplane slot.
Figure 1-8 Backplane (Rear View)
CPUs and Memories
The cell provides the processing and memory resources required by each sx2000 system
configuration. Each cell includes the following components: four processor module sockets, a
single cell (or coherency) controller ASIC, a high-speed crossbar interface, a high-speed I/O
interface, eight memory controller ASICs, capacity for up to 32 double-data rate (DDR) DIMMs,
high-speed clock distribution circuitry, a management subsystem interface, scan (JTAG) circuitry
for manufacturing test, and a low-voltage DC power interface. Figure 1-9 shows the locations
of the major components.
30 Overview
