32180 Datasheet, PDF (816/839 Pages) Renesas Technology Corp – 32-Bit RISC Single-Chip Microcomputers M32R Family M32R/ECU Series

Appendix 4 SUMMARY OF PRECAUTIONS
Appendix 4.8 Precautions about the Multijunction Timers
Appendix 4.8.10 Precautions on Using TML Measure Input
The following describes precautions to be observed when using TML measure input.
• If measure event input and write to the counter occur in the same clock period, the write value is set in the
counter, whereas the up-count value (before being rewritten) is latched into the measure register.
• If clock bus 1 is selected and any clock other than BCLK/2 is used for the timer, the counter cannot be
written normally. Therefore, when using any clock other than BCLK/2, do not write to the counter.
• If clock bus 1 is selected and any clock other than BCLK/2 is used for the timer, the value captured into the
measure register is one count larger the counter value. During the count clock to BCLK/2 period interval,
however, the captured value is exactly the counter value.
The diagram below shows the relationship between counter operation and the valid data that can be captured.
• When BCLK/2 is selected
BCLK/2
Counter
A
B
C
D
E
F
Captured
A
B
C
D
E
F
• When clock bus 1 is selected
BCLK/2
Count clock
Counter
A
B
C
Captured
B
C
D
Figure 4.8.3 Mistimed Counter Value and the Captured Value
Appendix 4-11
32180 Group User's Manual (Rev. 1.0)