Rev. 1.0, 09/01, page 532 of 904
2. Free-running count operation and periodic count operation
Immediately after a reset, the TPU’s TCNT counters are all designated as free-running
counters. When the relevant bit in TSTR is set to 1 the corresponding TCNT counter starts up-
count operation as a free-running counter. When TCNT overflows (changes from H'FFFF to
H'0000), the TCFV bit in TSR is set to 1. If the value of the corresponding TCIEV bit in TIER
is 1 at this point, the TPU requests an interrupt. After overflow, TCNT starts counting up again
from H'0000.
Figure 11.3 illustrates free-running counter operation.
TCNT value
H'FFFF
H'0000
CST bit
TCFV
Time
Figure 11.3 Free-Running Counter Operation
When compare match is selected as the TCNT clearing source, the TCNT counter for the
relevant channel performs periodic count operation. The TGR register for setting the period is
designated as an output compare register, and counter clearing by compare match is selected
by means of bits CCLR2 to CCLR0 in TCR. After the settings have been made, TCNT starts
count-up operation as a periodic counter when the corresponding bit in TSTR is set to 1. When
the count value matches the value in TGR, the TGF bit in TSR is set to 1 and TCNT is cleared
to H'0000.
If the value of the corresponding TGIE bit in TIER is 1 at this point, the TPU requests an
interrupt. After a compare match, TCNT starts counting up again from H'0000.
Figure 11.4 illustrates periodic counter operation.
Содержание H8S/2376 F-ZTAT
Страница 24: ...Rev 1 0 09 01 page xxiv of xliv ...
Страница 38: ...Rev 1 0 09 01 page xxxviii of xliv ...
Страница 44: ...Rev 1 0 09 01 page xliv of xliv ...
Страница 60: ...Rev 1 0 09 01 page 16 of 904 ...
Страница 96: ...Rev 1 0 09 01 page 52 of 904 ...
Страница 116: ...Rev 1 0 09 01 page 72 of 904 ...
Страница 148: ...Rev 1 0 09 01 page 104 of 904 ...
Страница 284: ...Rev 1 0 09 01 page 240 of 904 ...
Страница 422: ...Rev 1 0 09 01 page 378 of 904 ...
Страница 634: ...Rev 1 0 09 01 page 590 of 904 ...
Страница 656: ...Rev 1 0 09 01 page 612 of 904 ...
Страница 668: ...Rev 1 0 09 01 page 624 of 904 ...
Страница 780: ...Rev 1 0 09 01 page 736 of 904 ...
Страница 796: ...Rev 1 0 09 01 page 752 of 904 ...
Страница 806: ...Rev 1 0 09 01 page 762 of 903 ...
Страница 808: ...Rev 1 0 09 01 page 764 of 904 ...
Страница 921: ...Rev 1 0 09 01 page 877 of 904 ø tBRQOD tBRQOD Figure 24 24 External Bus Request Output Timing ...
Страница 938: ...Rev 1 0 09 01 page 894 of 904 ...