MC68HC05PV8 Datasheet, PDF (124/196 Pages) Freescale Semiconductor, Inc – Techinal Data - rev 1.9

Technical Data
Freescale Semiconductor, Inc.
9.2 Introduction
The MC68HC(8)05PV8/A has one 16-bit timer with two channels. The
timer consists of a 16-bit free running counter driven by a fixed
divide-by-four pre-scaler. This timer can be used for many purposes
including input waveform measurements while simultaneously
generating an output waveform. Pulse widths can vary from several
microseconds to many seconds. The output compare is improved so that
it is now possible to link the two output compares to one output in order
to generate pulses as short as E/4. Refer to Figure 9-1 for a timer block
diagram.
Because the timer has a 16-bit architecture each specific functional
segment is represented by two registers. These registers contain the
high and low byte of that functional segment. Generally, accessing the
low byte of a specific timer function allows full control of that function;
however, an access of the high byte inhibits that specific timer function
until the low byte is also accessed.
The I bit in the CCR should be set while manipulating both the high and
low byte register of a specific timer function to ensure that an interrupt
does not occur.
Technical Data
MC68HC(8)05PV8/A — Rev. 1.9
16-Bit Programmable Timer
For More Information On This Product,
Go to: www.freescale.com