
CHAPTER 8 8-BIT TIMER/EVENT COUNTERS 2 TO 5
User’s Manual U15905EJ2V1UD
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(b) Operation based on CRn register transitions
Figure 8-6. Timing of Operation Based on CRn Register Transitions
When the value of the CRn register changes from N to M before the rising edge of the FFH clock
→ The value of the CRn register is reloaded at the overflow that occurs immediately after.
N N + 1 N + 2
M
N
<1> CRn transition (N
→ M)
M
M + 1 M + 2
M M +1M + 2
FFH
02H
00H 01H
FFH
02H
00H 01H
Count clock
TMn count value
CRn
TMCEn
H
INTTMn
TOn
<2>
When the value of the CRn register changes from N to M after the rising edge of the FFH clock
→ The value of the CRn register is reloaded at the second overflow.
N N + 1 N + 2
N
NN
<1> CRn transition (N
→ M)
M
N + 1 N + 2
M M + 1 M + 2
FFH
03H
02H
00H 01H
FFH
02H
00H 01H
Count clock
TMn count value
CRn
TMCEn
H
INTTMn
TOn
<2>
Caution
In the case of reload from the CRn register between <1> and <2>, the value that is actually
used differs (Read value: M; Actual value of CRn register: N).
Remark
n = 2 to 5