Stopwatch Timer; Configuration Of Stopwatch Timer; Controlling Operating Clock - Epson S1C63003 Technical Manual

10

Stopwatch Timer

10.1

Configuration of Stopwatch Timer

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.
SWCKE
OSC1
f
OSC1
oscillation
Clock
circuit manager
(f )
OSC1
SWDIR
P01
Direct
input
P00 control
P02, P03,
DKM[2:0]
P10–P13
LCURF
SWCKE
OSC1
f
OSC1
oscillation Clock
circuit
manager
(f
)
OSC1
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.
10.2

Controlling Operating Clock

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.
If it is not necessary to run the stopwatch timer, stop the clock supply by setting SWCKE to "0" to reduce current
consumption.
S1C63003/004/008/016 TeChniCal Manual
(Rev. 1.1)
SWRST
/ (1,000 Hz)
32
1,000 / 1,024 1/1,000 sec
prescaler counter
Capture
control
circuit
SWRUN
EDIR
CRNWF
(a) S1C63004/008/016
SWRUN SWRST
/ (1,000 Hz)
32
1,000 / 1,024 1/1,000 sec
prescaler counter
Capture
control
circuit
(b) S1C63003
Figure 10. 1.1 Block diagram of stopwatch timer
Table 10. 2.1 Controlling stopwatch timer operating clock
SWCKE
1
0
Seiko epson Corporation
1/100 sec 1/10 sec
counter counter
Capture buffer
SWD[3:0] SWD[7:4]
reading reading
Data bus
1/100 sec 1/10 sec
counter counter
Capture buffer
SWD[3:0] SWD[7:4]
reading reading
Data bus
Stopwatch timer clock
f / 32 (1 kHz)
OSC1
Off
10 STOPWaTCh TiMeR
1 Hz interrupt request
10 Hz interrupt request
SWD[11:8]
reading
Direct RUN interrupt request
Direct LAP interrupt request
1 Hz interrupt request
10 Hz interrupt request
SWD[11:8]
reading
10-1