w65c22 Western Design Center, Inc., w65c22 Datasheet - Page 7

• Manufacturer Part Number: w65c22
• Description: W65c22n And W65c22s Versatile Interface Adapter Via Datasheet
• Manufacturer: Western Design Center, Inc.

1. INTRODUCTION
The W65C22 (W65C22N and W65C22S) Versatile Interface Adapter (VIA) is a flexible I/O device for use with
the 65xx series microprocessor family. The W65C22 includes functions for programmed control of two
peripheral ports (Ports A and B). Two program controlled 8-bit bidirectional 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.
KEY FEATURES OF THE W65C22
• Advanced CMOS process technology for low
• Compatible with various versions of the
• Low power consumption
• Two 8-bit, bi-directional peripheral I/O Ports
• Two
• Serial bi-directional peripheral I/O Port
• Enhanced "handshake" features
power consumption
NMOS 6522 devices
Timer/Counters
16-bit
programmable
Figure 1-1 W65C22 Internal Architecture Block Diagram
Interval
•
•
•
•
•
•
Programmable Data Direction Registers
Latched Input/Output Registers on both I/O
Ports
TTL compatible output peripheral lines
Single 1.8V to 5V power supply
Bus and functionally compatible with high-
speed
microprocessor families.
Register and Chip Selects specified for
multiplexed operation
8/16-bit
65xx
as
well
other
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