NEC uPD78P078 - Manual (Page 267)

267
CHAPTER 10 8-BIT TIMER/EVENT COUNTERS 5 AND 6
10.5 8-Bit Timer/Event Counters 5 and 6 Precautions
(1) Timer start errors
An error with a maximum of one clock might occur concerning the time required for a match signal to be
generated after the timer starts. This is because 8-bit timer registers 5 and 6 are started asynchronously
with the count pulse.
Figure 10-19. 8-bit Timer Registers 5 and 6 Start Timings
(2) Compare registers 50 and 60 sets
The 8-bit compare registers (CR50 and CR60) can be set to 00H.
Thus, when an 8-bit compare register is used as an event counter, one-pulse count operation can be carried
out.
Figure 10-20. External Event Counter Operation Timings
Count Pulse
TM5, TM6 Count Value 00H
Timer Start
01H 02H 03H 04H
TI5, TI6 Input
CR50, CR60 00H
TM5, TM6 Count Value 00H 00H 00H 00H
TO5, TO6
Interrupt Request Flag