Samsung S3F80JB manual Org, Through P3.1

Models: S3F80JB

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COUNTER A

S3F80JB

 

 

PROGRAMMING TIP — To generate 38 kHz, 1/3duty signal through P3.1

This example sets Counter A to the repeat mode, sets the oscillation frequency as the Counter A clock source, and CADATAH and CADATAL to make a 38 kHz, 1/3 Duty carrier frequency. The program parameters are:

8.795 us

17.59 us

37.9kHz 1/3 duty

Counter A is used in repeat mode

Oscillation frequency is 4 MHz (0.25 s)

CADATAH = 8.795 s / 0.25 s = 35.18, CADATAL = 17.59 s / 0.25 s = 70.36

Set P3.1 C-MOS push-pull output and CAOF mode.

44 pin package

 

ORG

0100H

; Reset address

START:

DI

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

LD

CADATAL,#(70-2)

; Set 17.5 ms

 

LD

CADATAH,#(35-2)

; Set 8.75 ms

 

 

 

;

 

 

LD

P3CON,#11110010B

; Set P3 to C-MOS push-pull output.

 

 

 

; Set P3.1 to REM output

 

 

 

;

 

 

LD

CACON,#00000110B

; Clock Source Fosc

 

 

 

; Disable Counter A interrupt.

 

 

 

; Select repeat mode for Counter A.

 

 

 

;

Start Counter A operation.

 

 

 

;

Set Counter A Output Flip-flop(CAOF) high.

 

 

 

;

 

 

LD

P3,#80H

; Set P3.7(Carrier On/Off) to high.

 

 

 

; This command generates 38 kHz, 1/3duty pulse signal

 

 

 

; through P3.1

 

 

 

;

 

12-6

Page 267
Image 267
Samsung S3F80JB manual Org, Through P3.1