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S3C8248/C8245/P8245/C8247/C8249/P8249
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PROGRAMMING TIP — To generate 38 kHz, 1/3duty signal through P3.0
This example sets Timer B to the repeat mode, sets the oscillation frequency as the Timer B clock source, and
TBDATAH and TBDATAL to make a 38 kHz,1/3 Duty carrier frequency. The program parameters are:
— Timer B is used in repeat mode
— Oscillation frequency is 4 MHz (0.25 µs)
— TBDATAH = 8.795 µs/0.25 µs = 35.18, TBDATAL = 17.59 µs/0.25 µs = 70.36
— Set P3.0 to TBPWM mode.
ORG
START
DI
•
•
•
LD
LD
LD
LD
•
•
•
8.795 µ s
17.59 µ s
37.9 kHz 1/3 Duty
0100H
TBDATAL,#(70-2)
TBDATAH,#(35-2)
TBCON,#00000110B
P3CONL,#02H
; Reset address
; Set 17.5 µs
; Set 8.75 µs
; Clock Source ← fxx
; Disable Timer B interrupt.
; Select repeat mode for Timer B.
; Start Timer B operation.
; Set Timer B Output flip-flop (TBOF) high.
;
; Set P3.0 to TBPWM mode.
; This command generates 38 kHz, 1/3 duty pulse signal
through P3.0.
8-BIT TIMER A/B
11-9
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