SN7489 Datasheet | Texas Instruments

SN7489 64-BIT RANDOM-ACCESS READ/WRITE MEMORY - For Application as a"Scratch Pad" Memory with Nondestructive Read-Out - Fully Decoded Memory Organized as 16 Words of Four Bits Each - Fast Access Time . . . 3 3 ns Typical - Diode-Clamped, Buffered Inputs - Open-Collector Outputs Provide Wire-AND Capability - Typical Power Dissipation . . . 3 7 5 mW - patible with Most TTL Circuits description This 64-bit active-element memory is a monolithic, high-speed, transistor-transistor logic (TTL) array of 64 flip-flop memory cells organized in a matrix to provide 16 words of four bits each. Each of the 16 words is addressed in straight binary with full on-chip decoding. The buffered memory inputs consist of four address lines, four data inputs, a write enable, and a memory enable for controlling the entry and access of data. The memory has opencollector outputs which may be wired-AND connected to permit expansion up to 4704 words of N-bit length without additional output buffering. Access time is typically 33 nanoseconds; power dissipation is typically 375 milliwatts. D1416, DECEMBER 1972-REV1SED FEBRUARY 1984 SN7489 . J OR N PACKAGE (TOP VIEWI AO C . ME C 2 WE C 3 01 C 4 Q1 : 5 D2 C 6 Q2 C 7 GND C 8 U , 6 H VCC 15 3 A 1 14 D A 2 13 J A 3 12 U D 4 11 3 Q 4 10 H D 3 9 ] Q3 logic symbol AO 111 A1 (15| A2 (14) A3 (13) me^L T77F (31 -Cs, RAM 1 6 X 4 (4) - 2 - (61 0 3 - (101 D4 - (12) 1 A, 2D >1 ^ ^ A, 1. 3 | ~ ^ ^ ^...