I
NTEL
® X
EON
® P
ROCESSOR
7500 S
ERIES
U
NCORE
P
ROGRAMMING
G
UIDE
UNCORE PERFORMANCE MONITORING
2-95
2.7 M-Box
Performance
Monitoring
2.7.1
Overview of the M-Box
The memory controller interfaces to the Intel
®
7500 Scalable Memory Buffers and translates read and
write commands into specific Intel
®
Scalable Memory Interconnect (Intel
®
SMI) operations. Intel SMI is
based on the FB-DIMM architecture, but the Intel 7500 Scalable Memory Buffer is not an AMB2 device
and has significant exceptions to the FB-DIMM2 architecture. The memory controller also provides a
variety of RAS features, such as ECC, memory scrubbing, thermal throttling, mirroring, and DIMM
sparing. Each socket has two independent memory controllers, and each memory controller has two
Intel SMI channels that operate in lockstep.
2.7.2 Functional
Overview
The memory controller is the interface between the home node controller (B-Box) and the Intel
Scalable Memory Interconnect and basically translates read and write commands into specific memory
commands and schedules them with respect to memory timing. The other main function of the memory
controller is advanced ECC support. There are two memory controllers per socket, each controlling two
Intel SMI channels in lockstep. Because of the data path affinity to the B-Box data path, each B-Box is
paired with a memory controller, that is, B-Boxes and memory controllers come in pairs.
Figure 2-2. Memory Controller Block Diagram
The memory controller interfaces to the router through the B-Box (home node coherence controller)
and to the P-Box pads.
mapper
dispatch
queue
page
table
DRAM
command
issue
and
timing
retry
queue
payload queue
accu
mula
tor
byte
mer
ge
victim
buffer
ECC
gen
FBD
packe
tizer
FBD
CRC
gen
err
inject
deacc
umula
tor
fill
buffer
FBD
depack
etizer
FBD
CRC
check
ECC check
control logic
scheduler
data path
Bbox
cmd
Bbox
ack
Bbox
data
data
to
Bbox
Intel®
SMI
Frame
Intel®
SMI
Frame