MT42C4256

Austin Semiconductor, Inc. 256K X 4 VRAM 256K x 4 DRAM with 512K x 4 SAM AVAILABLE AS MILITARY SPECIFICATIONS SMD 5962-89497 MIL-STD-883 SMJ44C251B MT42C4256 PIN ASSIGNMENT (Top View) VRAM 28-Pin DIP (C) (400 MIL) SC SDQ1 SDQ2 TR\/OE\ DQ1 DQ2 ME\/WE\ NC RAS\ A8 A6 A5 A4 Vcc 1 2 3 4 5 6 7 8 9 10 11 12 13 14 28 27 26 25 24 23 22 21 20 19 18 17 16 15 Vss SDQ4 SDQ3 SE\ DQ4 DQ3 DSF CAS\ QSF A0 A1 A2 A3 A7 28-Pin SOJ (DCJ) 28-Pin LCC (EC) SC SDQ1 SDQ2 TR\/OE\ DQ1 DQ2 ME\/WE\ NC RAS\ A8 A6 A5 A4 Vcc 1 2 3 4 5 6 7 8 9 10 11 12 13 14 28 27 26 25 24 23 22 21 20 19 18 17 16 15 Vss SDQ4 SDQ3 SE\ DQ4 DQ3 DSF CAS\ QSF A0 A1 A2 A3 A7 FEATURES Class B High-Reliability Processing DRAM: 262144 Words × 4 Bits SAM: 512 Words × 4 Bits Single 5-V Power Supply (±10% Tolerance) Dual Port Accessibility–Simultaneous and Asynchronous Access From the DRAM and SAM Ports Bidirectional-Data-Transfer Function Between the DRAM and the Serial-Data Register 4 × 4 Block-Write Feature for Fast Area Fill Operations; As Many as Four Memory Address Locations Written per Cycle From an On-Chip Color Register Write-Per-Bit Feature for Selective Write to Each RAM I/O; Two Write-Per-Bit Modes to Simplify System Design Enhanced Page-Mode Operation for Faster Access CAS-Before-RAS (CBR) and Hidden Refresh Modes All Inputs/Outputs and Clocks Are TTL Compatible Long Refresh Period: Every 8 ms (Max) Up to 33-MHz Uninterrupted Serial-Data Streams 3-State Serial I/Os Allow Easy Multiplexing o...