Basic Timer (Bt); Basic Timer Control Register (Btcon) - Samsung S3C9454B User Manual

BASIC TIMER and TIMER 0

BASIC TIMER (BT)

BASIC TIMER CONTROL REGISTER (BTCON)

The basic timer control register, BTCON, is used to select the input clock frequency, to clear the basic timer
counter and frequency dividers, and to enable or disable the watchdog timer function.
A Reset clears BTCON to "00H". This enables the watchdog function and selects a basic timer clock frequency of
f /4096. To disable the watchdog function, you must write the signature code "1010B" to the basic timer register
OSC
control bits BTCON.7–BTCON.4.
The 8-bit basic timer counter, BTCNT, can be cleared during normal operation by writing a "1" to BTCON.1. To
clear the frequency dividers for both the basic timer input clock and the timer 0 clock, you write a "1" to BTCON.0.
MSB
10-2
Basic Timer Control Register (BTCON)
.7 .6 .5
Watchdog timer enable bits:
1010B = Disable watchdog function
Other value = Enable watchdog
function
Basic timer input clock selection bits:
00 = fosc/4096
01 = fosc/1024
10 = fosc/128
11 = Invalid selection
NOTE: When you write a 1 to BTCON.0 (or BTCON.1), the basic timer
divider (or basic timer counter) is cleared. The bit is then cleared
automatically to 0.
Figure 10-1. Basic Timer Control Register (BTCON)
DCH, R/W
.4 .3 .2 .1
Basic timer counter clear bits:
0 = No effect
1 = Clear basic timer counter
.0 LSB
Divider clear bit for basic
timer and timer 0:
0 = No effect
1 = Clear both dividers
S3C9454B/F9454B