Samsung S3F80JB User Manual

Page 245

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BASIC TIMER and TIMER 0

S3F80JB

10-2

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 watch-dog timer function. It is located in Set 1 and
Bank0, address D3H, and is read/write addressable using register addressing mode.

A reset clears BTCON to '00H'. This enables the watch-dog function and selects a basic timer clock frequency of
fOSC/4096. To disable the watch-dog function, you must write the signature code '1010B' to the basic timer
register control bits BTCON.7–BTCON.4. For improved reliability, using the watch-dog timer function is
recommended in remote controllers and hand-held product applications.

Basic Timer Control Register (BTCON)

D3H, Set 1, Bank 0 , R/W

.7

.6

.5

.4

.3

.2

.1

.0

MSB

LSB

Divider Clear Bit for BT and T0:
0 = No effect
1 = Clear both dividers

Basic Timer Counter Clear Bits:
0 = No effect
1 = Clear BTCNT

Watch-dog Timer Enable Bits:
1010B = Disable watch-dog function
Others = Enable watch-dog function

Basic Timer Input Clock Selection Bits:
00 = f

OSC

/4096

01 = f

OSC

/1024

10 = f

OSC

/128

11 = Invalid selection

Figure 10-1. Basic Timer Control Register (BTCON)

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