Stopwatch Timer (Swt); Stopwatch Timer Overview - Epson S1C17001 Technical Manual

16 Stopwatch Timer (SWT)

16.1 Stopwatch Timer Overview

The S1C17001 incorporates a 1/100-second and 1/10-second stopwatch timer. The stopwatch timer consists of a
4-bit 2-stage BCD counter (1/100 and 1/10 second) that uses the 256 Hz signal divided from the OSC1 clock as the
input clock and allows count data to be read out by software.
The stopwatch timer can also generate interrupts using the 100 Hz (approximately 100 Hz), 10 Hz (approximately
10 Hz), and 1 Hz signals.
Figure 16.1.1 illustrates the stopwatch timer configuration.
OSC
OSC1 oscillator/
256Hz
division circuit
Interrupt enable
To ITC
S1C17001 TECHNICAL MANUAL
Count
SWTRST
Reset control
circuit
RUN/STOP
SWTRUN
control
SIE100
SIE10
Interrupt
SIE1 control
circuit
Interrupt request
Figure 16.1.1: Stopwatch timer configuration
1/100-second
Feedback
circuit 4-bit BCD counter
division
Approximate 100 Hz
Approximate 10 Hz
1Hz
EPSON
16 STOPWATCH TIMER (SWT)
Stopwatch timer
1/10-second
4-bit BCD counter
189