AK536256W

The Accutek AK536256W high density memory module is a CMOS dynamic RAM organized in 256K x 36 bit words. The module consists of eight standard 256K x 4 DRAMs in plastic SOJ packages and four 256K x 1 DRAMs in PLCC packages.

The assembly has 12 drams mounted on the front side of a printed circuit board in a 72 pad leadless SIM configuration.

The operation of the AK536256W is identical to eight 256K x 4 plus four 256K x 1 DRAMs. There are four CAS lines and two RAS lines. Independent byte control is accomplished by four CAS lines. Each separate CAS line controls two 256K x 4 DRAMs, along with one 256K x 1 DRAM with data in tied to data out to form a 9 bit byte.

The bank of 36 bits is controlled by the two RAS lines. An eighteen bit data path can be produced by connecting DQ0 to DQ18, DQ1 to DQ19, etc. and alternately strobing RAS₀ and RAS₂.