HYS72T[64/128/256]4[00/20]HFA–[2.5/3S/3.7]–B
Fully-Buffered DDR2 SDRAM Modules
Internet Data Sheet
Rev.1.01, 2007-06-20
10062006-RQWY-GI6S
4
1.2
Description
This document describes the electrical and mechanical
features of a 240-pin, PC2-4200F, PC2-5300F, ECC type,
Fully Buffered Double-Data-Rate Two Synchronous DRAM
Dual In-Line Memory Modules (DDR2 SDRAM FB-DIMMs).
Fully Buffered DIMMs use commodity DRAMs isolated from
the memory channel behind a buffer on the DIMM. They are
intended for use as main memory when installed in systems
such as servers and workstations. PC2-4200F, PC2-5300F,
refers to the DIMM naming convention indicating the DDR2
SDRAMs running at 266, 333, MHz clock speed and offering
4200, 5300, MB/s peak bandwidth. FB-DIMM features a
novel architecture including the Advanced Memory Buffer.
This single chip component, located in the center of each
DIMM, acts as a repeater and buffer for all signals and
commands which are exchanged between the host controller
and the DDR2 SDRAMs including data in- and output. The
AMB communicates with the host controller and / or the
adjacent DIMMs on a system board using an Industry
Standard
High-Speed
Differential
Interface at 1.5 V.
The Advanced Memory Buffer also allows buffering of
memory traffic to support large memory capacities. All
memory control for the DRAM resides in the host, including
memory request initiation, timing, refresh, scrubbing, sparing,
configuration access, and power management. The
Advanced Memory Buffer interface is responsible for handling
channel and memory requests to and from the local DIMM
and for forwarding requests to other DIMMs on the memory
channel. Fully Buffered DIMM provides a high memory
bandwidth, large capacity channel solution that has a narrow
host interface. The maximum memory capacity is 288 DDR2
SDRAM devices per channel or 8 DIMMs.
Point-to-Point
Link
Min. Row Active Time
Min. Row Cycle Time
t
RAS
t
RC
45
60
45
60
45
60
ns
ns
QAG Speed Code
–2.5
–3S
–3.7
Unit
DRAM Speed Grade
DDR2–800E
DDR2–667D
DDR2–533C
Module Speed Grade
PC2–6400E
PC2–5300D
PC2–4200C
CAS-RCD-RP latencies
6–6–6
5–5–5
4–4–4