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Functional Description
3
MPC750 Processor
The MCP750HA is designed to support the enhanced version of the
MPC750 360-pin BGA processor chip with 32MB to 256MB of ECC
DRAM, 1MB of level 2 cache (L2 cache), and up to 9MB of Flash
memory. The L2 cache and 1MB of 16-bit Flash memory reside on the
MCP750HA base board. The ECC DRAM and 8MB of additional (64-bit)
Flash memory are located on the RAM300 memory mezzanine.
The MPC750 is a 64-bit processor with 64KB on-chip cache (32KB data
cache and 32KB instruction cache). The L2 cache is implemented with an
on-chip, two way set associative tag memory and with external
synchronous SRAMs for data storage.
The Raven bridge controller ASIC provides the bridge between the
MPC750 microprocessor bus and the PCI local bus. Electrically, the Raven
chip is a 64-bit PCI connection. Four programmable map decoders in each
direction provide flexible addressing between the MPC750
microprocessor bus and the PCI local bus.
Flash Memory
The MCP750HA base board has provision for 1MB of 16-bit Flash
memory in two 8-bit sockets. The RAM300 memory mezzanine
accommodates 8MB of additional 64-bit Flash memory.
The onboard monitor/debugger, PPCBug, resides in the Flash chips.
PPCBug provides functionality for:
❏
Booting the operating system
❏
Initializing after a reset
❏
Displaying and modifying configuration variables
❏
Running self-tests and diagnostics
❏
Updating firmware ROM
Under normal operation, the Flash devices are in read-only mode, their
contents are pre-defined, and they are protected against inadvertent writes
due to loss of power conditions. However, for programming purposes,
Summary of Contents for MCP750HA Series
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