32186 datasheet(997/1032 Pages) RENESAS

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SUMMARY OF PRECAUTIONS

Appendix 4

Appendix 4-7

32185/32186 Group Hardware Manual

Rev.1.10 REJ09B0235-0110 May 15, 07

Appendix 4.9 Notes on Multijunction Timers

Appendix 4.9.1 Notes on using TOP single-shot output mode

The following describes precautions to be observed when using TOP single-shot output mode.

• If the counter stops due to an underflow in the same clock period as the timer is enabled by external input, the

former has priority so that the counter stops.

• If the counter stops due to an underflow in the same clock period as count is enabled by writing to the enable

bit, the latter has priority so that count is enabled.

• If the timer is enabled by external input in the same clock period as count is disabled by writing to the enable

bit, the latter has priority so that count is disabled.

• Because the timer operates synchronously with the count clock, a count clock-dependent delay is included

before F/F output is inverted after the timer is enabled.

• When writing to the correction register, be careful not to cause the counter to overflow. Even if the counter

overflows due to correction of counts, no interrupt requests are generated for reasons of an overflow. There-

fore, if the counter underflows in the subsequent down-count after an overflow, a false interrupt request is

generated for an underflow that includes the overflowed count.

32186 Datasheet(PDF) 997 Page - Renesas Technology Corp