Peripheral Interface Adapter: Difference between revisions

Revision as of 02:20, 19 June 2005

Revision as of 18:08, 22 September 2005

Line 1:

The '''Peripheral Interface Adapter''' (PIA) is a [[peripheral]] [[integrated circuit]] providing parallel I/O interfacing capability for [[microprocessor]] systems. Common PIAs include the [[Motorola]] MC6820 and MC6821, and the [[MOS Technology]] MCS6520, all of which are functionally identical but have slightly different electrical characteristics. The PIA is most commonly packaged in a 40 pin [[Dual in-line package|DIP package]].

The PIA is designed for glueless connection to the [[Motorola 6800]] style [[bus]], and provides 20 I/O lines, which are organised into 2 8-bit bidirectional ports (or 16 general-purpose I/O lines) and 4 control lines (for handshaking and interrupt generation). The directions for all 16 general lines (PA0-7, PB0-7) can be programmed independently. The control lines can be programmed to generate interrupts, automatically generate handshaking signals for devices on the I/O ports, or output a plain high or low signal.