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R01UH0336EJ0102 Rev.1.02
Page 951 of 1538
Jul 17, 2014
V850E2/PG4-L
Section 17 OS Timer (OSTM)
The OSTMnTINT interrupt-generation period depends on the timing for
updating of the OSTMnCMP register and the counter value at the time. For
the formula to calculate the period for generation of the OSTMnTINT
interrupt, refer to the table below.
Note
A, B, C and D indicate the values of OSTMnCMP over the intervals thus
labeled in Figure 17-9, Timing Diagram of OS Timer in Free-Running
Comparison Mode.
Forced restart
Forced restarting does not proceed during counting even if the
OSTMnTS.OSTMnTS bit is set, or if OSTMnTSST is high when the
synchronous start trigger is in use.
The counter ignores the attempted setting and continues counting.
Table 17-7
OSTMnTINT Generation Timing
Old Value
for
Compari-
son
New
Value for
Compari-
son
Counter Value at the
Time of Rewriting
Period of OSTMnTINT Generation
Label in
Timing
Diagram
Counter starts
(A + 1)
counter clock period
(a)
A
A
No rewriting
(FFFF FFFF
H
+ 1)
counter clock period
(b)
B
C > B
B < counter value < C
(C - B)
counter clock period
(c)
C
D < C
Counter value > D, C
(FFFF FFFF
H
- C + D + 1)
counter clock
period
(d)