Samsung 8-Bit Manual do Utilizador descarregar pdf (Página 402)

100

101

TIMER 1 S3C9228/P9228

11-2

Timer 1 Control Register (TACON)

You use the timer 1 control register, TACON, to

— Enable the timer 1 operating (interval timer)

— Select the timer 1 input clock frequency

— Clear the timer 1 counter, TACNT and TBCNT

— Enable the timer 1 interrupt

TACON is located in page 0, at address BBH, and is read/write addressable using register addressing mode.

A reset clears TACON to "00H". This sets timer 1 to disable interval timer mode, selects an input clock frequency

of fxx/512, and disables timer 1 interrupt. You can clear the timer 1 counter at any time during normal operation

by writing a "1" to TACON.3.

To enable the timer 1 interrupt, you must write TACON.7, TACON.2, and TACON.1 to "1".

To generate the exact time interval, you should write TACON.3 and INTPND2.0, which cleared counter and

interrupt pending bit. To detect an interrupt pending condition when T1INT is disabled, the application program

polls pending bit, INTPND.2.0. When a "1" is detected, a timer 1 interrupt is pending. When the T1INT sub-

routine has been serviced, the pending condition must be cleared by software by writing a "0" to the timer 1

interrupt pending bit, INTPND2.0.

Timer A Control Register (TACON)

BBH, R/W

.7 .6 .5 .4 .3 .2 .1 .0MSB LSB

Timer 1/A interrupt enable bit:

0 = Disable interrupt

1 = Enable interrupt

Not used

Timer 1/A counter enable bit:

0 = Disable counting operation

1 = Enable counting operation

Timer 1/A counter clear bit:

0 = No affect

1 = Clear the timer 1/A counter (when write)

One 16-bit timer or Two 8-bit timers

mode:

0 = Two 8-bit timers mode (Timer A/B)

1 = One 16-bit timer mode (Timer 1)

Timer 1/A clock selection bits:

000 = fxx/512

001 = fxx/256

010 = fxx/64

011 = fxx/8

100 = fxx

101 = fxt (sub clock)

110 = T1CLK (external clock)

111 = Not available

Figure 11-1. Timer 1 Control Register (TACON)

1 2 ... 397 398 399 400 401 402 403 404 405 406 407 ... 461 462

Comentários a estes Manuais

Sem comentários

Samsung 8-Bit Manual do Utilizador Página 402

Comentários a estes Manuais

Manuais e produtos relacionados com não Samsung 8-Bit