TMP92CZ26A

92CZ26A-286

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 (T A1OUT).

Example: To output a 3.2μs square wave pulse from the TA1OUT pin at fC= 50 MHz,

use the following procedure to make the appropriate register settings. This

example uses T MRA 1; however, either TMRA0 or TMRA1 may b e 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 φT1 (0.16 μs at fC = 50
MHz) as the input clock.
TA1REG
0 0 0 0 1 0 1 0 Set the timer register to 3.2 μs ÷ φT1 ÷ 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 0X
PMFC
X X X X 1X Set PM1 to function as the TA1OUT pin.
TA01RUN
X X X 11 Start TMRA1 counting.
X: Don’t care, : No change

Figure 3.12.17 Square Wave Output Timing Chart (50% duty)

1.6
μ
s at fC
=
50 MHz
0 1 2 3 0 1 2 3 0 1 2 3 0
φT1
TA01RUN
<TA01RUN>
Bit7 to Bit2
Bit1
Bit0
INTTA1
TA1FF
TA1OUT
Up
counter
Comparato
r
timing
Comparator output
(Match detect)
UC1 clea
r