User manual

B-4 SPARC Enterprise M8000/M9000 Servers Service Manual • June 2010
B.1 CPU Memory Board Unit
The CPU memory board unit (CMU) consists of a CPU memory board (CMB) with a
DC-DC converter mounted, a memory, and a CPU module (CPUM). It can be
combined with an I/O unit to configure a system (domain).
FIGURE B-1 shows the CMU.
FIGURE B-1 CPU Memory Board Unit (CMU)
The CMU has the following characteristics.
■ Active maintenance of CMUs is possible using the DR function.
■ In CMU maintenance, you can replace the target in units of CMU as a whole, CPU
module, or memory. To perform active maintenance, you need to pull out the
CMU from the system before replacing the target.
■ A CMU can be installed or removed using the DR function during system
operation.
■ A dedicated LSI is mounted for system control (SC) and memory access control
(MAC).