WDC 65C22

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W65C22S Versatile Interface Adapter

[edit] Introduction

The W65C22S Versatile Interface Adapter (VIA) is a flexible I/O device for use with the 65xx series microprocessor family. The W65C22S includes functions for programmed control of two peripheral ports (Ports A and B). Two program controlled 8-bit bi-directional peripheral I/O ports allow direct interfacing between the microprocessor and selected peripheral units. Each port has input data latching capability. Two programmable Data Direction Registers (A and B) allow selection of data direction (input or output) on an individual line basis. Also provided are two programmable 16-bit Interval Timer/Counters with latches. Timer 1 may be operated in a One-Shot Interrupt Mode with interrupts on each count-to-zero, or in a Free-Run Mode with a continuous series of evenly spaced interrupts. Timer 2 functions as both an interval and pulse counter. Serial Data transfers are provided by a serial to parallel/parallel to serial shift register. Application versatility is further increased by various control registers, including an Interrupt Flag Register, an Interrupt Enable Register and two Function Control Registers. The IRQB output is an open drain.

[edit] Features of the W65C22S

Advanced CMOS process technology for low power consumption Compatible with NMOS 6522 devices Low power consumption Two 8-bit, bi-directional peripheral I/O Ports Two 16-bit programmable Interval Timer/Counters Serial bi-directional peripheral I/OPort Enhanced "handshake" feature Latched Input/Output Registers on both I/OPorts Programmable Data Direction Registers TTL compatible I/O peripheral lines Single 1.8V to 5V power supply Bus compatible with high-speed W65C02S and W65C816S Register and Chip Selects specified for multiplexed operation