M32C80 Datasheet, PDF (155/352 Pages) Renesas Technology Corp – 16/32-BIT SINGLE-CHIP MICROCOMPUTER M16C FAMILY / M32C/80 SERIES

M32C/80 Group
14. Timer (Timer A)
14.1.1 Timer Mode
In timer mode, the timer counts an internally generated count source (see Table 14.3). Figure 14.8
shows the TAiMR register (i=0 to 4) in timer mode.
Table 14.3 Timer Mode Specifications
Item
Specification
Count Source
f1, f8, f2n(1), fC32
Counting Operation
• The timer decrements a counter value
When the timer counter underflows, content of the reload register is reloaded into the
count register and counting resumes.
Divide Ratio
1/(n+1) n: setting value of the TAi register (i=0 to 4) 000016 to FFFF16
Counter Start Condition
The TAiS bit in the TABSR register is set to "1" (starts counting)
Counter Stop Condition
The TAiS bit is set to "0" (stops counting)
Interrupt Request Generation Timing The timer counter underflows
TAiIN Pin Function
Programmable I/O port or gate input
TAiOUT Pin Function
Programmable I/O port or pulse output
Read from Timer
The TAi register indicates counter value
Write to Timer
• While the timer counter stops, the value written to the TAi register is also written to
both reload register and counter
• While counting, the value written to the TAi register is written to the reload register
(It is transferred to the counter at the next reload timing)
Selectable Function
• Gate function
Input signal to the TAiIN pin determines whether the timer counter starts or stops counting
• Pulse output function
The polarity of the TAiOUT pin is inversed whenever the timer counter underflows
NOTE:
1. The CNT3 to CNT0 bits in the TCSPR register select no division (n=0) or divide-by-2n (n=1 to 15).
Rev. 1.00 Nov. 01, 2005 Page 136 of 330
REJ09B0271-0100