Samsung S3F80JB Programming TIP To generate a one-pulse signal through P3.1, CADATAH,# Set 40 ms

S3F80JB COUNTER A

PROGRAMMING TIP — To generate a one-pulse signal through P3.1

This example sets Counter A to the one shot mode, sets the oscillation frequency as the Counter A clock source, and CADATAH and CADATAL to make a 40 ∝s width pulse. The program parameters are:

40 us

—Counter A is used in one-shot mode

—Oscillation frequency is 4 MHz ( 1 clock = 0.25 ∝s)

—CADATAH = 40 ∝s / 0.25 ∝s = 160, CADATAL = 1

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

—44 pin package

	ORG	0100H	; Reset address
START:	DI
	•
	•
	LD	CADATAH,# (160-2)	; Set 40 ms
	LD	CADATAL,# 1	; Set any value except 00H
			;
	LD	P3CON,#11110010B	; Set P3 to C-MOS push-pull output.
			; Set P3.1 to REM output
			;
	LD	CACON,#00000001B	; Clock Source → Fosc
			; Disable Counter A interrupt.
			; Select one shot mode for Counter A.
			; Stop Counter A operation.
			; Set Counter A Output Flip-Flop (CAOF) high
	LD	P3,#80H	; Set P3.7(Carrier On/Off) to high.
	•
	•
	•
Pulse_out:	LD	CACON,#00000101B	; Start Counter A operation
			; to make the pulse at this point.
	•		; After the instruction is executed, 0.75 ms is required
	•		; before the falling edge of the pulse starts.
	•

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