225
CHAPTER 9 8-BIT TIMER/EVENT COUNTER
(3) Square-wave output operation
The 8-bit timer/event counters 1 and 2 output a square wave with any selected frequency at intervals specified
by the value set in advance to 8-bit compare registers 10 and 20 (CR10 and CR20).
The TO1/P31 or TO2/P32 pin output status is reversed at intervals of the count value preset to CR10 or CR20
by setting bit 0 (TOE1) or bit 4 (TOE2) of the 8-bit timer output control register (TOC1) to 1. This enables
a square wave with any selected frequency to be output.
Table 9-8. 8-bit Timer/Event Counters 1 and 2 Square-Wave Output Ranges
Minimum Pulse Time
Maximum Pulse Time
Resolution
MCS = 1
MCS = 0
MCS = 1
MCS = 0
MCS = 1
MCS = 0
2
×
1/f
X
(400 ns)
2
2
×
1/f
X
(800 ns)
2
9
×
1/f
X
(102.4
μ
s)
2
10
×
1/f
X
(204.8
μ
s)
2
×
1/f
X
(400 ns)
2
2
×
1/f
X
(800 ns)
2
2
×
1/f
X
(800 ns)
2
3
×
1/f
X
(1.6
μ
s)
2
10
×
1/f
X
(204.8
μ
s)
2
11
×
1/f
X
(409.6
μ
s)
2
2
×
1/f
X
(800 ns)
2
3
×
1/f
X
(1.6
μ
s)
2
3
×
1/f
X
(1.6
μ
s)
2
4
×
1/f
X
(3.2
μ
s)
2
11
×
1/f
X
(409.6
μ
s)
2
12
×
1/f
X
(819.2
μ
s)
2
3
×
1/f
X
(1.6
μ
s)
2
4
×
1/f
X
(3.2
μ
s)
2
4
×
1/f
X
(3.2
μ
s)
2
5
×
1/f
X
(6.4
μ
s)
2
12
×
1/f
X
(819.2
μ
s)
2
13
×
1/f
X
(1.64 ms)
2
4
×
1/f
X
(3.2
μ
s)
2
5
×
1/f
X
(6.4
μ
s)
2
5
×
1/f
X
(6.4
μ
s)
2
6
×
1/f
X
(12.8
μ
s)
2
13
×
1/f
X
(1.64 ms)
2
14
×
1/f
X
(3.28 ms)
2
5
×
1/f
X
(6.4
μ
s)
2
6
×
1/f
X
(12.8
μ
s)
2
6
×
1/f
X
(12.8
μ
s)
2
7
×
1/f
X
(25.6
μ
s)
2
14
×
1/f
X
(3.28 ms)
2
15
×
1/f
X
(6.55 ms)
2
6
×
1/f
X
(12.8
μ
s)
2
7
×
1/f
X
(25.6
μ
s)
2
7
×
1/f
X
(25.6
μ
s)
2
8
×
1/f
X
(51.2
μ
s)
2
15
×
1/f
X
(6.55 ms)
2
16
×
1/f
X
(13.1 ms)
2
7
×
1/f
X
(25.6
μ
s)
2
8
×
1/f
X
(51.2
μ
s)
2
8
×
1/f
X
(51.2
μ
s)
2
9
×
1/f
X
(102.4
μ
s)
2
16
×
1/f
X
(13.1 ms)
2
17
×
1/f
X
(26.2 ms)
2
8
×
1/f
X
(51.2
μ
s)
2
9
×
1/f
X
(102.4
μ
s)
2
9
×
1/f
X
(102.4
μ
s)
2
10
×
1/f
X
(204.8
μ
s)
2
17
×
1/f
X
(26.2 ms)
2
18
×
1/f
X
(52.4 ms)
2
9
×
1/f
X
(102.4
μ
s)
2
10
×
1/f
X
(204.8
μ
s)
2
11
×
1/f
X
(409.6
μ
s)
2
12
×
1/f
X
(819.2
μ
s)
2
19
×
1/f
X
(104.9 ms)
2
20
×
1/f
X
(209.7 ms)
2
11
×
1/f
X
(409.6
μ
s)
2
12
×
1/f
X
(819.2
μ
s)
Remarks 1.
f
X
: Main system clock oscillation frequency
2.
MCS : Bit 0 of oscillation mode selection register (OSMS)
3.
Values in parentheses apply to operation with f
X
= 5.0 MHz.