upd70f3017ay Renesas Electronics Corporation., upd70f3017ay Datasheet - Page 184

• Manufacturer Part Number: upd70f3017ay
• Description: V850/sa1tm 32-/16-bit Single-chip Microcontroller
• Manufacturer: Renesas Electronics Corporation.

7.2.7 Cautions
(1) Error on starting timer
(2) Setting 16-bit capture/compare register (in mode in which clear & start occurs on match between TMn
(3) Setting compare register during timer count operation
184
An error of up to 1 clock occurs before the match signal is generated after the timer has been started. This is
because 16-bit timer register n (TMn) is started asynchronously to the count pulse.
and CRn0)
Set 16-bit capture/compare registers n0 and n1 (CRn0, CRn1) to a value other than 0000H. When using these
registers as event counters, a one-pulse count operation is not possible.
If the value to which the current value of 16-bit capture/compare register n0 (CRn0) has been changed is less
than the value of 16-bit timer register n (TMn), TMn continues counting, overflows, and starts counting again from
0.
If the new value of CRn0 (M) is less than the old value (N), the timer must be reset and restarted after the value
of CRn0 has been changed.
Remark
Remark
Remarks 1. N > X > M
Figure 7-26. Timing After Changing Compare Register During Timer Count Operation
TMn count value
n = 0, 1
n = 0, 1
2. n = 0, 1
Count pulse
TMn count value
CRn0
Count pulse
Figure 7-25. Start Timing of 16-Bit Timer Register n
CHAPTER 7 TIMER/COUNTER FUNCTION
X
N
–
Timer starts
1
0000H
User’s Manual U12768EJ4V1UD
X
0001H
M
0002H
FFFFH
0003H
0000H
0004H
0001H
0002H