Operation Timing Of Ovfn Flag - NEC V850/SA1 mPD703015 Preliminary User's Manual

(4) Setting valid edge
Before setting the valid edge of the TIn0 pin, stop the timer operation by resetting bits 2 and 3 (TMCn2 and
TMCn3) of the 16-bit timer mode control register n to 0, 0. Set the valid edge by using bits 4 and 5 (ESn00 and
ESn01) of the prescaler mode register n (PRMn).
(5) Re-triggering one-shot pulse
(a) One-shot pulse output by software
When a one-shot pulse is output, do not set OSPTn to 1. Do not output the one-shot pulse again until
INTTMn0, which occurs on coincidence between TMn and CRn0, occurs.
(b) One-shot pulse output with external trigger
If the external trigger occurs while a one-shot pulse is output, it is ignored.
(6) Operation of OVFn flag
The OVFn flag is set to "1" in the following case:
Select mode in which timer 0 is cleared and started on coincidence between TMn and CRn0
↓
Set CRn0 to FFFFH.
↓
When TMn counts up from FFFFH to 0000H
Remark n = 0, 1
CHAPTER 7 TIMER/COUNTER FUNCTION
Figure 7-33. Operation Timing of OVFn Flag
Count pulse
CRn0
FFFFH
TMn
FFFEH FFFFH
OVFn
INTTMn0
0000H 0001H
177