INS8254
INS8254 is N-Channel Bit Programmable Peripherallnterface manufactured by National Semiconductor.
Description
Features
The INSS254 is an LSI device which provides two S-bit ports of peripheral interfacing capability for microputer systems. The I/O chip contains two peripheral ports of eight bits each. Each of the I/O pins in the two ports may be defined as an input or an output to provide maximum flexibility. Each port may be read from or written to in a parallel (S-bit byte) mode. To improve efficiency and simplify programming in control-based applications, a single bit of I/O in either port may be set, cleared or read with a single micropro Cessor instruction. In addition to basic I/O, one of the ports, port A, may be programmed to operate in several types of strobed mode with handshake. Strobed mode together with optional interrupt operation permit both high speed parallel data transfers and interface to a wide variety of peripherals with no external logic.
The INS8254 is an n-channel silicon gate device packaged in a 40-pin dual-in-line package. It operates with a single 5-volt power supply and is fully TTL patible.
- Single +5-volt power supply
- Low power dissipation
- Fully static operation
- pletely TTL patible
- Two S-bit programmable,I/O ports
- I/O port A has TRI-STATE® capability
- Handshake controls for strobed mode of operation
- Single bit I/O operations with single instruction
- Reduces system package count
- Direct interface with SC/MP-II
- MICROBUS TM- patible
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INS8254 MICROBUS Configuration r'- cs
AS-AD
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RESET
INTR
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