Embedded Systems Design, 2nd Edition

Memory systems 81

found on SIMM memory modules but as systems move away from

implementing parity memory — many PC motherboards no

longer do so — the need for such devices will decline.

By 4 organisation

This configuration has effectively replaced the × 1 memory

in microprocessor applications because of its reduced address bus

loading and complexity — only 8 chips are needed to build a 32 bit

wide data path instead of 32 and only two are needed for an 8 bit

wide bus.

By 8 and by 9 organisations

Wider memories such as the × 8 and × 9 are beginning to

replace the × 4 parts in many applications. Apart from higher

integration, there are further reductions in ...