TMP92CF30
2009-06-12
92CF30-255
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 3.2
μ
s square wave pulse from the TA1OUT pin at f
SYS
=
50 MHz, use the following procedure to
make the appropriate register settings. This example uses TMRA1; however, either TMRA0 or TMRA1 may be
used.
* Clock state
Clcok gear :
1/1
Prescaler of clock gear : 1/2
7 6 5 4 3
2
1
0
TA01RUN
← −
X X X
−
−
0
−
Stop TMRA1 and clear it to “0”.
TA01MOD
←
0 0 X X 0
1
X
X
Select 8-bit timer mode and select
φ
T1 (0.16
μ
s at f
SYS
=
50 MHz) as the input clock.
TA1REG
←
0
0
0
0
1
0
1
0
Set the timer register to 3.2
μ
s
÷
φ
T1
÷
2
=
0AH
TA1FFCR
←
X
X
X
X
1
0
1
1
Clear TA1FF to “0” and set it to invert on the match detect
signal from TMRA1.
PM
← −
X X X X
−
0
X
PMFC
← −
X X X X
−
1
X
Set PM1 to function as the TA1OUT pin.
TA01RUN
← −
X X X
−
1
1
−
Start TMRA1 counting.
X: Don’t care,
−
: No change
Figure 3.12.16 Square Wave Output Timing Chart (50% duty)
1.6
μ
s at f
C
=
50 MHz
0 1 2
3
0
1 2
3
0
1 2
3
0
φ
T1
TA01RUN
<TA01RUN>
Bit7 to Bit2
Bit1
Bit0
INTTA1
TA1FF
TA1OUT
Up
counter
Comparator
timing
Comparator output
(Match detect)
UC1 clear
Summary of Contents for TLCS-900/H1 Series
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