KS57C2308/P2308/C2316/P2316

TIMERS and TIMER/COUNTERS

 

 

WATCH TIMER MODE REGISTER (WMOD)

The watch timer mode register WMOD is used to select specific watch timer operations. It is 8-bit write-only addressable. An exception is WMOD bit 3 (the XTIN input level control bit) which is 1-bit read-only addressable.

A RESET automatically sets WMOD.3 to the current input level of the subsystem clock, XTIN (high, if logic one; low, if logic zero), and all other WMOD bits to logic zero.

F88H

WMOD.3

WMOD.2

WMOD.1

WMOD.0

 

 

 

 

 

F89H

WMOD.7

"0"

WMOD.5

WMOD.4

 

 

 

 

 

In summary, WMOD settings control the following watch timer functions:

— Watch timer clock selection

(WMOD.0)

 

— Watch timer speed control

(WMOD.1)

 

Enable/disable watch timer

(WMOD.2)

 

— XTIN input level control

(WMOD.3)

 

Buzzer frequency selection

(WMOD.4 and WMOD.5)

 

Enable/disable buzzer output

(WMOD.7)

 

 

 

 

 

Table 11-8. Watch Timer Mode Register (WMOD) Organization

 

 

 

 

 

 

 

 

 

 

 

Bit Name

Values

 

Function

Address

 

 

 

 

 

 

 

 

 

 

 

WMOD.7

 

0

 

Disable buzzer (BUZ) signal output

F89H

 

 

 

 

 

 

 

 

 

 

 

 

 

1

 

Enable buzzer (BUZ) signal output

 

 

 

 

 

 

 

 

 

 

 

 

WMOD.6

 

0

 

Always logic zero

 

 

 

 

 

 

 

 

 

 

 

 

WMOD.5–.4

0

 

0

 

2 kHz buzzer (BUZ) signal output

 

 

 

 

 

 

 

 

 

 

 

 

 

0

 

1

 

4 kHz buzzer (BUZ) signal output

 

 

 

 

 

 

 

 

 

 

 

 

 

1

 

0

 

8 kHz buzzer (BUZ) signal output

 

 

 

 

 

 

 

 

 

 

 

 

 

1

 

1

 

16 kHz buzzer (BUZ) signal output

 

 

 

 

 

 

 

 

 

 

 

 

WMOD.3

 

0

 

Input level to XTIN pin is lo; 1-bit read only

F88H

 

 

 

 

1

 

Input level to XTIN pin is high; 1-bit read only

 

 

 

WMOD.2

 

0

 

Disable watch timer; clear frequency dividing circuits

 

 

 

 

 

 

 

 

 

 

 

 

 

1

 

Enable watch timer

 

 

 

 

 

 

 

 

 

 

 

WMOD.1

 

0

 

Normal mode; sets IRQW to 0.5 seconds

 

 

 

 

 

 

 

 

 

 

 

 

 

1

 

High-speed mode; sets IRQW to 3.91 ms

 

 

 

 

 

 

 

 

 

 

 

WMOD.0

 

0

 

Select the system clock (fxx/128) as the watch timer clock (fw)

 

 

 

 

 

 

 

 

 

 

 

 

 

1

 

Select subsystem clock as watch timer clock (fw)

 

 

 

 

 

 

 

 

 

 

NOTE: System clock frequency (fxx) is assumed to be 4.19 MHz; subsystem clock (fxt) is assumed to be 32.768 kHz.

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Image 247
Samsung KS57C2308 manual Watch Timer Mode Register Wmod