MC68B40中文资料摩托罗拉数据手册PDF规格书

Programmable Timer Module(PTM)

The MC6840 is a programmable subsystem component of the M6800 Family designed to provide variable system time intervals.

The MC6840 has three 16-bits binary counters, three corresponding control registers, and status register. These counters are under software control and may be used to cause system interrupts and or generate output signals.