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Chapter 6 8-bit Timers
8-bit Event Count
M
N
00 01 02 N-1
N
00 01
TMnIO
input
TMnEN
flag
Compare
register
Binary
counter
Interrupt
request flag
6-4 8-bit Event Count
6-4-1 Operation
Event count operation has 2 types ; TMnIO input and synchronous TMnIO input can be selected as the
count clock.
8-bit Event Count Operation
Event count means that the binary counter (TMnBC) counts the input signal from external to the TMnIO
pin. If the value of the binary counter reaches the setting value of the compare register (TMnOC), inter-
rupts can be generated at the next count clock.
Count Timing of TMnIO Input (Timers 0, 1, 4 and 5)
When TMnIO input is selected, TMnIO input signal is directly input to the count clock of the timer n. The
binary counter counts up at the falling edge of the TMnIO input signal.
Table 6-4-1 Event Count Input Clock
Figure 6-4-1 Count Timing of TMnIO Input (Timers 0, 1, 4 and 5)
When the TMnIO input is selected for count clock source and the value of the timer n binary
counter is read during operation, incorrect value at count up may be read out. To prevent
this, use the event count by synchronous TMnIO input, as the following page.
Timer 0Timer 2Timer 4Timer 5
TM0IO input TM1IO input TM4IO input TM5IO input
(P11) (P76) (P13) (P77)
Synchronous
TM0IO input
Synchronous
TM1IO input
Synchronous
TM4IO input
Synchronous
TM5IO input
Event Input