Samsung S3C8245 User Manual

F 

This example sets Timer B to the one shot  mode, sets the oscillation frequency as the Timer B clock source, and
TBDATAH and TBDATAL to make a 40 

µ

s width pulse. The program parameters are:

40 

µ

s

— Timer B is used in one shot mode

— Oscillation frequency is 4 MHz (1 clock = 0.25

 µ

s)

— TBDATAH = 40

 µ

s / 0.25

 µ

s = 160, TBDATAL = 1

— Set P3.0 to TBPWM mode

ORG

0100H

;

Reset address

START

DI

•

•

•

LD

TBDATAH,# (160-2)

;

Set 40

 µ

s

LD

TBDATAL,# 1

;

Set any value except  00H

LD

TBCON,#00000001B

;

Clock Source  

←

  f

OSC

;

Disable Timer B interrupt.

;

Select one shot mode for Timer B.

;   Stop Timer B operation.
;   Set Timer B output flip-flop (TBOF) high

LD

P3CONL, #02H

;

Set P3.0 to TBPWM mode.

•

•

Pulse_out:

LD

TBCON,#00000101B

;

Start Timer B operation

;  to make the pulse at  this point.

•

;

After the instruction is executed, 0.75 

µ

s is required

•

;

before the falling edge of the pulse starts.

•