资料来源 : Free On-Line Dictionary of Computing
Dual In-line Memory Module
Small circuit boards carrying memory {integrated
circuits}, with signal and power pins on both sides of the
board, in contrast to {single-in-line memory modules} (SIMM).
The individual gold or lead connectors (pins) on SIMMs,
although they are on both sides of the chip, are connected to
the same memory chip, while on a DIMM, the connections on each
side of the module connect to different chips. This allows
for a wider data path, as more modules can be accessed at
once. DIMM pins are arranged in a zigzag design to allow PCB
tracks to pass between them.
The 8-byte DIMM format with dual-sided contacts can
accommodate 4- and 16-megabit {dynamic RAM} chips, and is
predicted to handle 64- and 256-Mbit devices. The 8-byte DIMM
will hold up to 32 megabytes of memory using 16-Mbit DRAMs,
but with the 256-Mbit future-generation DRAM, it will be able
to hold a 64-Mx64 configuration. Another variation, the
72-pin {SO-DIMM}, is designed to connect directly to 32 bit
data buses, and is intended for use in memory-expansion
applications in {notebook computers}.
A Dual in-line memory module (DIMM), as opposed to SIMMs (used
by the majority of the PC industry) allows for a 128-bit data
path by interleaving memory on alternating memory access
cycles. SIMMs on the other hand, have a 64-bit data path.
Suppliers are unanimous in their belief that the DIMM will
eventually replace the SIMM as the market's preferred memory
module.
(1996-01-28)