SMJ44C251B 262144 BY 4-BIT MULTIPORT VIDEO RAM

SGMS058A - MARCH 1995 - REVISED JUNE 1995

features

Military Operating Temperature Range -55°C to 125°C
Performance Ranges:
ACCESS ACCESS ACCESS ACCESS
TIME TIME TIME TIME
ROW COLUMN SERIAL SERIAL
ADDRESS ENABLE DATA ENABLE
(MAX) (MAX) (MAX) (MAX)
t_a(R) t_a(C) t_a(SQ) t_a(SE)
'44C251B-10 100 ns 25 ns 30 ns 20 ns
'44C251B-12 120 ns 30 ns 35 ns 25 ns
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 of Video-Data Streams
512 Selectable Serial-Register Starting Locations
Packaging:
- 28-Pin J-Leaded Ceramic Chip Carrier Package (HJ Suffix)
- 28-Pin Leadless Ceramic Chip Carrier Package (HM Suffix)
- 28-Pin Ceramic Sidebrazed DIP (JD Suffix)
- 28-Pin Zig-Zag In-Line (ZIP), Ceramic Package (SV Suffix)
Split Serial-Data Register for Simplified Real-Time Register Reload

description

The SMJ44C251B multiport video RAM is a high-speed, dual-ported memory device. It consists of a dynamic random-access memory (DRAM) organized as 262144 words of 4 bits each interfaced to a serial-data register or serial-access memory (SAM) organized as 512 words of 4 bits each. The SMJ44C251B supports three types of operation: random access to and from the DRAM, serial access to and from the serial register, and bidirectional transfer of data between any row in the DRAM and the serial register. Except during transfer operations, the SMJ44C251B can be accessed simultaneously and asynchronously from the DRAM and SAM ports.

Title: 262144 BY 4-BIT MULTIPORT VIDEO RAM
Product Family: VRAM
Device Functionality: 1M(256KX4)
Orderable Devices: 5962-8949704MMA, SM44C251B-10HJM, SM44C251B-12HJM, SMJ44C251B-10HJM, SMJ44C251B-10HMM, SMJ44C251B-10JDM, SMJ44C251B-12HJM, SMJ44C251B-12HMM, SMJ44C251B-12JDM, SMJ44C251B-12SVM

View the complete PDF datasheet: sgms058a.pdf (904 K Bytes) (Requires Acrobat Reader 3.x)

View more information about generic part numbers:SMJ44C251B

Go to the Engineering Design Center to locate information on other TI Semiconductor devices.