Hardware Reference
In-Depth Information
Small-outline dual-inline memory module (SODIMM)
Small-outline dual-inline memory modules are enhanced versions of standard
DIMM devices. A 72-pin small-outline DIMM is about half the length of a
72-pin SIMM.
Small-outline J-lead (SOJ) packaged memory
Small-outline J-lead packages are commonly used for surface-mounted DRAM
devices. The package is rectangular with J-shaped connecting pins on the two
long sides.
Static random access memory (SRAM)
Static RAM (SRAM) is a type of RAM that requires no refreshing and retains
its data as long as power is applied. Provided that the data is not changing (i.e.
remains
static
), SRAM devices require very little power. SRAM is frequently
used to provide cache memory.
Thin small-outline packaged (SOP) memory
Thin small-outline packages are an alternative to SOJ packages for surface-
mounting DRAM devices. TSOP packages are approximately one-third of the
thickness of an SOJ. TSOP components are often found in small-outline DIMMs
and credit card memory.
Un-buffered memory
An un-buffered memory device does not have internal buffers or registers. See
Buffered memory and Registered memory.
Video random access memory (VRAM)
Video
RAM
is
special
dual-ported
memory
(two
separate
data
ports
are
provided) fitted to a video or graphics card.
Zero wait state memory
Zero wait state memory offers fast access times because older and slower mem-
ory devices may require between one and five wait states (i.e. do-nothing cycles)
to slow a CPU down to match the access time of the RAM.
Memory size
The amount of memory required by a PC depends not only on the software
applications that are installed but also on the operating system that is used.
