CHAPTER 7 8-BIT TIMER/EVENT COUNTER
158
User’s Manual U11302EJ4V0UM
Remark
Interval time = (N + 1)
x t: N = 00H to FFH
7.4 8-Bit Timer/Event Counter Operations
7.4.1 8-bit timer/event counter mode
(1) Interval timer operations
The 8-bit timer/event counter operates as an interval timer that generates interrupt requests repeatedly
at intervals of the count value preset to the 8-bit compare registers (CR10 and CR20).
When the count values of 8-bit timer registers 1 and 2 (TM1 and TM2) match the values set to CR10 and
CR20, counting continues with the TM1 and TM2 values cleared to 0 and interrupt request signals (INTTM1
and INTTM2) are generated.
The count clock of TM1 can be selected using bits 0 to 3 (TCL10 to TCL13) of timer clock select register
1 (TCL1). The count clock of TM2 can be selected using bits 4 to 7 (TCL14 to TCL17) of timer clock select
register 1 (TCL1).
For the operation when the value of the compare register is changed during timer count operation, refer
to
7.5 8-Bit Timer/Event Counter Operating Precautions (3)
.
Figure 7-8. Interval Timer Operation Timing
t
00
TM1 count value
Count clock
CR10
INTTM1
TO1
01
N
00
01
N
00
01
N
Count start
Clear
Clear
Interrupt request acknowledgment
N
N
N
N
Interrupt request acknowledgment
Interval time
Interval time
Interval time
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