KM428C256

The KM428C256 is a CMOS 256K*8 bit dual port DRAM. It includes a 256K*8 dynamic random acess memory (RAM) port and 512*8 static serial access memory (SAM) port. The RAM and SAM ports operate asynchronously except during data transfer between the ports. The RAM array consists of 512 bit rows of 4096 bits while the SAM port consists of eight 512 bit high speed shift registers that are connected to the RAM array through a 4096 bit data transfer gate.

There are some features of KM428C256 as follows: (1)fast page mode; (2)RAM read, write, read-modify-write; (3)serial read and serial write; (4)read real time read and split read transfer (RAMSAM); (5)write, split write transfer with masking operation (NEW MASK); (6)block write, flash write and write per bit with masking operation (NEW MASK); (7)common data I/O using three state RAM output control; (8)all inputs and outputs TTL and CMOS compatible; (9)refresh: 512 cycles/8 ms; (10)single +5 V±10% supply voltage; (11)plastic 40-pin 400 mil SOJ and 475 mil ZIP 40/44-pin plastic TSOP (type II).

What comes next is about the maximum ratings of KM428C256: (1)voltage on any pin relative to VSS, VIN, VOUT: -1 to +7.0 V; (2)voltage on VCC supply relative to VSS, VIN, VOUT: -1 to +7.0 V; (3)storage temperature, Tstg: -55 to +150; (4)power dissipation, PD: 1 W; (5)short circuit output current, IOS: 50 mA.