User's Manual

S3C9228/P9228 WATCH TIMER
12-3
WATCH TIMER CIRCUIT DIAGRAM
WT INT Enable
WTCON.1
WTCON.2
WTCON.3
WTCON.4
WTCON.5
WTCON.6
Enable/Disable
Selector
Circuit
MUX
INTPND2.3
WTINT
WTCON.6
fW/2
15
fW/2
14
fW/2
13
fW/2
7
fW/64 (0.5 kHz)
fW/32 (1 kHz)
fW/16 (2 kHz)
fW/8 (4 kHz)
(1 Hz)
fX = Main clock (where fx = 4.19 MHz)
fxt = Sub clock (32,768 Hz)
fW = Watch timer frequency
Clock
Selector
Frequency
Dividing
Circuit
fW
32.768 kHz
fxt
fLCD = 2048 Hz
WTCON.7
WTCON.0
8
BUZ (P0.3)
fx/128
Figure 12-2. Watch Timer Circuit Diagram