10 STOPWaTCh TiMeR
S1C63003/004/008/016 TeChniCal Manual
Seiko epson Corporation
10-1
(Rev. 1.1)
Stopwatch Timer
10
Configuration of Stopwatch Timer
10.1
The S1C63003/004/008/016 has a 1/1,000 sec stopwatch timer. The stopwatch timer is configured of a 3-stage, 4-bit
BCD counter serving as the input clock of a 1,000 Hz signal output from the prescaler. Data can be read out four
bits (1/1,000 sec, 1/100 sec and 1/10 sec) at a time by software. In addition the S1C63004/008/016 has a direct input
function that controls the stopwatch timer RUN/STOP and LAP using the input ports P00 and P01. Figure 10.1.1 is
the block diagram of the stopwatch timer.
Clock
manager
SWCKE
f
OSC1
/
32
OSC1
oscillation
circuit
(f
OSC1
)
Data bus
1 Hz interrupt request
1,000 / 1,024
prescaler
1/1,000 sec
counter
1/100 sec
counter
1/10 sec
counter
Capture buffer
SWD[3:0]
reading
SWD[7:4]
reading
SWD[11:8]
reading
SWRST
10 Hz interrupt request
Capture
control
circuit
SWRUN
EDIR
CRNWF
DKM[2:0]
LCURF
Direct RUN interrupt request
Direct LAP interrupt request
(1,000 Hz)
Direct
input
control
SWDIR
P01
P00
P02, P03,
P10–P13
(a) S1C63004/008/016
Clock
manager
SWCKE
f
OSC1
/
32
OSC1
oscillation
circuit
(f
OSC1
)
Data bus
1 Hz interrupt request
1,000 / 1,024
prescaler
1/1,000 sec
counter
1/100 sec
counter
1/10 sec
counter
Capture buffer
SWD[3:0]
reading
SWD[7:4]
reading
SWD[11:8]
reading
SWRST
10 Hz interrupt request
Capture
control
circuit
(1,000 Hz)
SWRUN
(b) S1C63003
1.1 Block diagram of stopwatch timer
Figure 10.
The stopwatch timer can be used as a separate timer from the clock timer. In particular, digital watch stopwatch func-
tions can be realized easily with software.
Controlling Operating Clock
10.2
The clock manager generates the stopwatch timer operating clock by dividing the OSC1 clock by 32. Before the
stopwatch timer can be run, write "1" to the SWCKE register to supply the operating clock to the stopwatch timer.
2.1 Controlling stopwatch timer operating clock
Table 10.
SWCKE
Stopwatch timer clock
1
f
OSC1
/ 32 (1 kHz)
0
Off
If it is not necessary to run the stopwatch timer, stop the clock supply by setting SWCKE to "0" to reduce current
consumption.