Texas Instruments SN74ALS870DW

Register File Dual 8-CH Bipolar 24-Pin SOIC Tube
ICs, Latches Logic; Output Current:24mA; Propagation Delay:26ns; No. of Bits:4bit; Output Type:Tristate; Supply Voltage Range:4.5V to 5.5V; Logic Case Style:SOIC; No. of Pins:24; Operating Temperature Range:0°C to 70°C ;RoHS Compliant: Yes
This device features two 16-word by 4-bit register files. Each register file has individual write-enable (1W, 2W) controls and address lines. This device has two 4-bit data I/O ports (DQA1-DQA4 and DQB1-DQB4). The data I/O ports can output to bus A and bus B, receive input from bus A and bus B, receive input from bus A and output to bus B, or output to bus A and receive input from bus B. To prevent writing conflicts in the dual-input mode, the B-input port takes priority. Two select (S0 and S1) lines control which port has access to which register. S2 determines whether the A ports are in the input or the output modes and S3 does likewise for the B ports. The address lines (1A0-1A3 or 2A0-2A3) are decoded by an internal 1-of-16 decoder to select which register word is to be accessed. All outputs are 3-state buffer-type outputs designed specifically to drive bus lines directly. The SN74ALS870 is characterized for operation from 0°C to 70°C.