www.DataSheet4U.com
CHAPTER 10 WATCH TIMER
228
10.4 Watch Timer Operations
10.4.1 Watch timer operation
When the 32.768 kHz subsystem clock or 8.38 kHz main system clock is used, the timer operates as a watch timer
with a 0.5 second or 0.25 second interval. In addition, when the 4.19 MHz main system clock is used, the timer can
operate as a watch timer with a 0.5 second or 1 second interval.
Caution
When 8.38 MHz or 4.19 MHz frequency is used, the time interval is slightly off.
When f
X
= 8.38 MHz frequency is used,
2
8
×
2
14
=
2
22
= 0.5005136… (second)
f
X
8.38
×
10
6
When f
X
= 4.19 MHz frequency is used,
2
8
×
2
13
=
2
21
= 0.5005136… (second)
f
X
4.19
×
10
6
When f
XT
= 32.768 MHz frequency is used,
1
×
2
14
=
2
14
= 0.50000… (second)
f
XT
32.768
×
10
3
When f
X
= 10.0 MHz frequency is used (not intended),
2
8
×
2
14
=
2
22
= 0.4194304 (second)
f
X
10.0
×
10
6
The watch timer sets the interrupt request flag (WTIF) to 1 at the constant time interval. The standby state (STOP
mode/HALT mode) can be cleared by setting WTIF to 1.
When bit 2 (TMC22) of the watch timer mode control register (TMC2) is set to 0, the 5-bit counter is cleared and
the count operation stops.
For simultaneous operation of the interval timer, zero-second start can be achieved by setting TMC22 to 0
(maximum error: 15.6 ms when operated at f
XT
= 32.768 kHz).
Содержание 78014Y Series
Страница 2: ...www DataSheet4U com 2 MEMO...
Страница 8: ...www DataSheet4U com 8 MEMO...
Страница 22: ...www DataSheet4U com 22 MEMO...
Страница 30: ...www DataSheet4U com 30 MEMO...
Страница 34: ...www DataSheet4U com 34 MEMO...
Страница 62: ...www DataSheet4U com CHAPTER 2 OUTLINE PD78014Y Subseries 62 MEMO...
Страница 78: ...www DataSheet4U com CHAPTER 3 PIN FUNCTION PD78014 Subseries 78 MEMO...
Страница 94: ...www DataSheet4U com CHAPTER 4 PIN FUNCTION PD78014Y Subseries 94 MEMO...
Страница 170: ...www DataSheet4U com CHAPTER 7 CLOCK GENERATOR 170 MEMO...
Страница 222: ...www DataSheet4U com CHAPTER 9 8 BIT TIMER EVENT COUNTER 222 MEMO...
Страница 230: ...www DataSheet4U com CHAPTER 10 WATCH TIMER 230 MEMO...
Страница 262: ...www DataSheet4U com CHAPTER 14 A D CONVERTER 262 MEMO...
Страница 318: ...www DataSheet4U com CHAPTER 15 SERIAL INTERFACE CHANNEL 0 PD78014 Subseries 318 MEMO...
Страница 408: ...www DataSheet4U com CHAPTER 16 SERIAL INTERFACE CHANNEL 0 PD78014Y Subseries 408 MEMO...
Страница 446: ...www DataSheet4U com CHAPTER 17 SERIAL INTERFACE CHANNEL 1 446 MEMO...
Страница 472: ...www DataSheet4U com CHAPTER 18 INTERRUPT FUNCTIONS AND TEST FUNCTION 472 MEMO...
Страница 502: ...www DataSheet4U com CHAPTER 22 PD78P014 78P014Y 502 MEMO...
Страница 520: ...www DataSheet4U com CHAPTER 23 INSTRUCTION SET 520 MEMO...