AK491024S

MICROCIRCUIT CORPORATION DESCRIPTION The Accutek AK491024 high density memory module is a random access memory organized in 1 Meg x 9 bit words. The assembly consists of nine standard 1 Meg x 1 DRAMs in plastic leaded chip carriers (SOJ) mounted on the front side of a printed circuit board. The module can be configured as a leadless 30 pad SIM or a leaded 30 pin SIP. This packaging approach provides a 6 to 1 density increase over standard DIP packaging. The operation of the AK491024 is identical to nine 1 Meg x 1 DRAMs. For the lower eight bits data input is tied to the data output and brought out separately for each device, with common RAS, CAS control. This common I/O feature dictates the use of early-write cycles to prevent contention of D and Q. Since the Write-Enable (WE) signal must always go low before CAS in a write cycle, Read-Write and Read-Modify-Write operation is not possible. For the ninth bit, the data input (D9) and the data output (Q9) pins are brought out separately and controlled by a separate PCAS for that bit. Bit nine is generally used for parity. ACCUTEK AK491024S / AK491024G 1,048,576 Word x 9 Bit CMOS Dynamic Random Access Memory Front View 30-Pin SIM 1 30 30-Pin SIP 1 FEATURES · 1,048,576 x 9 bit organization · Optional 30 Pad leadless SIM (Single In-Line Module) or 30 Pin leaded SIP (Single In-Line Package) · JEDEC standard pinout · Common CAS and RAS control for the lower eight bits · Separate PCAS control for D9 and Q9 · CAS-before-RAS refr...