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CHAPTER 7 INTERRUPT
7.4.4
Multiple Interrupts
Multiple hardware interrupts can be implemented by setting different interrupt levels in
the interrupt level setting bits (IL0, IL1, IL2) of the interrupt control register (ICR) in
response to multiple interrupt requests from peripheral functions. Use of multiple
interrupts, however, is not possible with the extended intelligent I/O service.
■
Multiple Interrupts
●
Operation of multiple interrupts
During execution of an interrupt processing routine, if an interrupt request with a higher-priority interrupt
level is generated, the current interrupt processing is interrupted and the interrupt request with the higher-
priority interrupt level is accepted. When the interrupt request with the higher-priority interrupt level
terminates, the CPU returns to the previous interrupt processing.
0 to 7 can be set as the interrupt level. If level 7 is set, the CPU does not accept interrupt requests.
During execution of interrupt processing, if an interrupt request with the same or lower-priority interrupt
level is generated, the new interrupt request is held until the current interrupt terminates unless the I flag or
ILM is changed.
Other multiple interrupts to be activated during an interrupt can be temporarily disabled by setting the I flag
in the condition code register (CCR) in the interrupt processing routine to interrupts not allowed (CCR: I =
0) or the interrupt level mask register (ILM) to interrupts not allowed (ILM = 000
B
).
Note:
The extended intelligent I/O service (EI
2
OS) cannot be used for the activation of multiple interrupts.
During processing of the extended intelligent I/O service (EI
2
OS), all other interrupt requests and
extended intelligent I/O service requests are held.
●
Example of multiple interrupts
This example of multiple interrupt processing assumes that a timer interrupt is given a higher priority than
an A/D converter interrupt. In this example, the A/D converter interrupt level is set to "2", and the timer
interrupt level is set to "1". If a timer interrupt is generated during processing of the A/D converter
interrupt, the processing shown in Figure 7.4-5 is performed.
Содержание MB90460 Series
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Страница 45: ...26 CHAPTER 2 NOTES ON HANDLING DEVICES ...
Страница 83: ...64 CHAPTER 3 CPU ...
Страница 95: ...76 CHAPTER 4 RESET ...
Страница 107: ...88 CHAPTER 5 CLOCK ...
Страница 131: ...112 CHAPTER 6 LOW POWER CONSUMPTION MODE ...
Страница 175: ...156 CHAPTER 7 INTERRUPT ...
Страница 181: ...162 CHAPTER 8 MODE SETTING ...
Страница 223: ...204 CHAPTER 9 I O PORT ...
Страница 237: ...218 CHAPTER 10 TIME BASE TIMER ...
Страница 247: ...228 CHAPTER 11 WATCHDOG TIMER ...
Страница 275: ...256 CHAPTER 12 16 BIT RELOAD TIMER ...
Страница 373: ...354 CHAPTER 14 MULTI FUNCTIONAL TIMER ...
Страница 485: ...466 CHAPTER 16 PWC Timer ...
Страница 531: ...512 CHAPTER 17 UART ...
Страница 559: ...540 CHAPTER 19 DELAYED INTERRUPT GENERATOR MODULE ...
Страница 589: ...570 CHAPTER 20 8 10 BIT A D CONVERTER ...
Страница 601: ...582 CHAPTER 21 ROM CORRECTION FUNCTION ...
Страница 633: ...614 CHAPTER 23 512K 1024K BIT FLASH MEMORY ...
Страница 645: ...626 CHAPTER 24 EXAMPLE OF F2 MC 16LX MB90F462 F462A F463A CONNECTION FOR SERIAL WRITING ...
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Страница 716: ...697 INDEX INDEX The index follows on the next page This is listed in alphabetic order ...
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