198
CHAPTER 13 WATCH PRESCALER
13.4
Interrupts of Watch Prescaler
An interrupt request is generated when the selected interval time of the watch prescaler
has elapsed (interval timer function).
■
Interrupts in Operation of Interval Timer Function (Watch Interrupts)
In any mode other than the main stop mode, the watch interrupt request flag bit is set to "1" (WPCR:WTIF
= 1), when the watch prescaler counter counts up by using the source oscillation of the subclock and the
time of the interval timer has elapsed. If the interrupt request enable bit is also enabled (WPCR:WTIE = 1)
and watch counter start interrupt request enable bit of the watch counter is disabled (WCSR: ISEL0), an
interrupt request (IRQ20) occurs from watch prescaler to an interrupt controller.
•
Regardless of the value in the WTIE bit, the WTIF bit is set to "1" when the time set by the watch
interrupt interval time select bits has been reached.
•
When the WTIF bit is set to "1", changing the WTIE bit from the disable state to the enable state
(WPCR:WTIE = 0
→
1) immediately generates an interrupt request.
•
The WTIF bit cannot be set when the counter is cleared (WPCR:WCLR = 1) at the same time as the
selected bit overflows.
•
Write "0" to the WTIF bit in the interrupt processing routine to clear an interrupt request to "0".
Note:
When enabling the output of interrupt requests (WPCR:WTIE = 1) after canceling a reset, always
clear the WTIF bit at the same time (WPCR:WTIF = 0).
■
Interrupts of Watch Prescaler
■
Register and Vector Table Related to Interrupts of Watch Prescaler
*: The watch prescaler shares the same interrupt request number and vector table as the watch counter.
CHAPTER 8 INTERRUPTS describes the interrupt request numbers and vector tables for all peripheral
functions.
Table 13.4-1 Interrupts of Watch Prescaler
Item
Description
Interrupt condition
Interval time set by "WPCR:WTC1" and "WTC0" has elapsed.
Interrupt flag
WPCR:WTIF
Interrupt enable
WPCR:WTIE
Table 13.4-2 Register and Vector Table Related to Interrupts of Watch Prescaler
Interrupt
source
Interrupt
request No.
Interrupt level setup register
Vector table address
Register
Setting bit
Upper
Lower
Watch
prescaler*
IRQ20
ILR5
L20
FFD2
H
FFD3
H
Summary of Contents for F2 MC-8FX Family
Page 2: ......
Page 4: ......
Page 34: ...20 CHAPTER 1 DESCRIPTION ...
Page 38: ...24 CHAPTER 2 HANDLING DEVICES ...
Page 39: ...25 CHAPTER 3 MEMORY SPACE This chapter describes memory space 3 1 Memory Space 3 2 Memory Map ...
Page 56: ...42 CHAPTER 5 CPU ...
Page 73: ...59 CHAPTER 6 CLOCK CONTROLLER ...
Page 96: ...82 CHAPTER 6 CLOCK CONTROLLER ...
Page 104: ...90 CHAPTER 7 RESET ...
Page 105: ...91 CHAPTER 8 INTERRUPTS This chapter explains the interrupts 8 1 Interrupts ...
Page 174: ...160 CHAPTER 10 TIMEBASE TIMER ...
Page 184: ...170 CHAPTER 10 TIMEBASE TIMER ...
Page 218: ...204 CHAPTER 13 WATCH PRESCALER ...
Page 257: ...243 CHAPTER 16 8 16 BIT COMPOSITE TIMER ...
Page 261: ...247 CHAPTER 16 8 16 BIT COMPOSITE TIMER ...
Page 288: ...274 CHAPTER 16 8 16 BIT COMPOSITE TIMER ...
Page 301: ...287 CHAPTER 17 16 BIT PPG TIMER ...
Page 316: ...302 CHAPTER 17 16 BIT PPG TIMER ...
Page 382: ...368 CHAPTER 21 UART SIO DEDICATED BAUD RATE GENERATOR ...
Page 390: ...376 CHAPTER 22 I2C ...
Page 395: ...381 CHAPTER 22 I2C ...
Page 399: ...385 CHAPTER 22 I2C ...
Page 430: ...416 CHAPTER 23 10 BIT A D CONVERTER ...
Page 476: ...462 CHAPTER 24 LCD CONTROLLER ...
Page 482: ...468 CHAPTER 25 LOW VOLTAGE DETECTION RESET CIRCUIT ...
Page 494: ...480 CHAPTER 26 CLOCK SUPERVISOR ...
Page 507: ...493 CHAPTER 27 REAL TIME CLOCK ...
Page 523: ...509 CHAPTER 27 REAL TIME CLOCK ...
Page 532: ...518 CHAPTER 27 REAL TIME CLOCK ...
Page 536: ...522 CHAPTER 28 256 KBIT FLASH MEMORY ...
Page 554: ...540 CHAPTER 28 256 KBIT FLASH MEMORY ...
Page 564: ...550 CHAPTER 29 EXAMPLE OF SERIAL PROGRAMMING CONNECTION ...
Page 595: ...581 INDEX INDEX The index follows on the next page This is listed in alphabetic order ...
Page 596: ...582 INDEX Index ...
Page 597: ...583 INDEX ...
Page 600: ...586 Pin Function Index ...
Page 602: ......