CHAPTER 6 PERIPHERAL HARDWARE FUNCTION
154
User’s Manual U10676EJ3V0UM
(2) Time setting of timer counter
[Timer set time] (cycle) is calculated by dividing [contents of modulo re 1] by [count pulse (CP)
frequency] selected by the mode register.
T (sec) =
= (n+1)
(resolution)
where,
T (sec): Timer set time (seconds)
f
CP
(Hz): CP frequency (Hz)
n:
Contents of modulo register (n
≠
0)
Once the timer has been set, interrupt request flag IRQT2 is set at the set time interval of the timer.
Table 6-8 shows the resolution of each count pulse of the timer counter and the longest set time (time when FFH
is set to the modulo registers 1 and 2).
Table 6-8. Resolution and Longest Set Time (16-Bit Timer Counter Mode) (1/2)
(TM10 = 0, TM11 = 1, TM20 = 0, TM21 = 1)
(a)
µ
PD754144: at 1.0 MHz
Mode Register
16-Bit Timer Counter
TM26
TM25
TM24
Resolution
Longest Set Time
0
1
0
2
µ
s
131 ms
0
1
1
1
µ
s
65.5 ms
1
0
0
1024
µ
s
67.1 s
1
0
1
256
µ
s
16.8 s
1
1
0
64
µ
s
4.19 s
1
1
1
16
µ
s
1.05 s
(b)
µ
PD754244: at 6.0 MHz
Mode Register
16-Bit Timer Counter
TM26
TM25
TM24
Resolution
Longest Set Time
0
1
0
333 ns
21.8 ms
0
1
1
167 ns
10.9 ms
1
0
0
171
µ
s
11.2 s
1
0
1
42.7
µ
s
2.80 s
1
1
0
10.7
µ
s
699 ms
1
1
1
2.67
µ
s
175 ms
n+1
f
CP
.
Содержание PD754144
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