Epson S1C63666 Technical Manual page 86

CHAPTER 4: PERIPHERAL CIRCUITS AND OPERATION (Stopwatch Timer)
SWRUN: Stopwatch timer RUN/STOP (FF79H•D1)
This register controls the RUN/STOP of the stopwatch timer, and the operating status can be monitored
by reading this register.
• When writing data
When "1" is written: RUN
When "0" is written: STOP
The stopwatch timer enters the RUN status when "1" is written to SWRUN, and the STOP status when "0"
is written. In the STOP status, the timer data is maintained until the next RUN status or resets timer. Also,
when the STOP status changes to the RUN status, the data that was maintained can be used for resuming
the count. RUN/STOP control with this register is valid only when the direct input function is set to
disable. When the direct input function is set, it becomes invalid.
• When reading data
When "1" is read: RUN
When "0" is read: STOP
Reading is always valid regardless of the direct input function setting. "1" is read when the stopwatch
timer is in the RUN status, and "0" is read in the STOP status.
At initial reset, this register is set to "0".
LCURF: Lap data carry-up request flag (FF79H•D3)
This flag indicates a carry that has been generated to 1 sec-digit when the data is held. Note that this flag
is invalid when the direct input function is disabled.
When "1" is read: Carry is required
When "0" is read: Carry is not required
Writing: Invalid
If the capture buffer shifts into hold status while the 1 Hz interrupt factor flag ISW1 is set to "1", LCURF is
set to "1" to indicate that a carry-up to 1-sec digit is required. When performing a processing such as a
LAP input preceding with 1 Hz interrupt processing, read this flag before processing and check whether
carry-up is needed or not.
This flag is renewed (set/reset) every time the capture buffer shifts into hold status.
At initial reset, this flag is set to "0".
CRNWF: Capture renewal flag (FF79H•D2)
This flag indicates that the content of the capture buffer has been renewed.
When "1" is read: Renewed
When "0" is read: Not renewed
Writing: Invalid
The content of the capture buffer is renewed if the LAP key is input when the data held into the capture
buffer has not yet been read. Reading SWD8–11 in that status sets this flag to "1", and the hold status is
maintained. Consequently, when data that is held by a LAP input is read, read this flag after reading the
SWD8–11 and check whether the data has been renewed or not.
This flag is renewed when SWD8–11 is read.
At initial reset, this flag is set to "0".
EIRUN, EILAP, EISW1, EISW10: Interrupt mask registers (FFE6H)
These registers are used to select whether to mask the stopwatch timer interrupt.
When "1" is written: Enabled
When "0" is written: Masked
Reading: Valid
The interrupt mask registers EIRUN, EILAP, EISW1 and EISW10 are used to separately select whether to
mask the direct RUN, direct LAP, 1 Hz and 10 Hz interrupts.
At initial reset, these registers are set to "0".
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S1C63666 TECHNICAL MANUAL