UPD8253-5 Datasheet (NEC) - PROGRAMMABLE INTERVAL TIMER

UPD8253-5, PROGRAMMABLE INTERVAL TIMER

cs RD WR Al AO FUNCTION 0 1 0 0 0 Load Counter No.

0 0 1 0 0 1 Load Counter No.1 0 1 0 1 0 Load Counter No.2 0 1 0 1 1 Write Mode Word 0 0 1 0 0 Read Counter No.

0 0 0 1 0 1 Read Counter No.1 0 0 1 1 0 Read Counter No.2 0 0 1 1 1 No-Operation, 3-

NEe Microcomputers, Inc.

PROGRAMMABLE INTERVAL TIMER NEe p.PD8253 p.PD8253-5 DESCR IPTION The NEC flPD8253-5 contains three independent, programmable, multi-modal 16-bit counter/timers.

It is designed as a general purpose device, fully compatible with the 8080 family.

The flPD8253-5 interfaces directly to the busses of the processor as an array of I/O ports.

The flPD8253-5 can generate accurate time delays und~r the control of system software.

The three independent 16-bit counters can be cloc