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b.
Generating a 50% duty ratio square wave pulse
The state of the timer flip-flop (TA1FF) is inverted at constant intervals and its
status output via the timer output pin (TA1OUT).
Example: To output a 3.2μs square wave pulse from the TA1OUT pin at f
* Clock state
← −
TA01RUN
← 0
TA01MOD
← 0
TA1REG
← X
TA1FFCR
← −
PM
← −
PMFC
← −
TA01RUN
X: Don't care, −: No change
φT1
TA01RUN
<TA01RUN>
Bit7 to Bit2
Up
Bit1
counter
Bit0
0
Comparator
timing
Comparator output
(Match detect)
INTTA1
UC1 clear
TA1FF
TA1OUT
Figure 3.12.17 Square Wave Output Timing Chart (50% duty)
use the following procedure to make the appropriate register settings. This
example uses TMRA1; however, either TMRA0 or TMRA1 may be used.
Clcok gear :
Prescaler of clock gear : 1/2
7
6
5
4
3
2
1
−
−
X
X
X
0
0
X
X
0
1
X
0
0
0
1
0
1
X
X
X
1
0
1
−
X
X
X
X
0
−
X
X
X
X
1
−
X
X
X
1
1
1
2
3
0
92CZ26A-286
1/1
0
−
Stop TMRA1 and clear it to "0".
Select 8-bit timer mode and select φT1 (0.16 μs at f
X
MHz) as the input clock.
Set the timer register to 3.2 μs ÷ φT1 ÷ 2 = 0AH
0
1
Clear TA1FF to "0" and set it to invert on the match detect
signal from TMRA1.
X
Set PM1 to function as the TA1OUT pin.
X
−
Start TMRA1 counting.
1
2
3
0
1.6 μs at f
= 50 MHz
C
TMP92CZ26A
= 50 MHz,
C
1
2
3
0
= 50
C
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