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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.
Summary of Contents for MB90460 Series
Page 1: ...The following document contains information on Cypress products ...
Page 3: ......
Page 5: ......
Page 9: ...iv ...
Page 41: ...22 CHAPTER 1 OVERVIEW ...
Page 45: ...26 CHAPTER 2 NOTES ON HANDLING DEVICES ...
Page 83: ...64 CHAPTER 3 CPU ...
Page 95: ...76 CHAPTER 4 RESET ...
Page 107: ...88 CHAPTER 5 CLOCK ...
Page 131: ...112 CHAPTER 6 LOW POWER CONSUMPTION MODE ...
Page 175: ...156 CHAPTER 7 INTERRUPT ...
Page 181: ...162 CHAPTER 8 MODE SETTING ...
Page 223: ...204 CHAPTER 9 I O PORT ...
Page 237: ...218 CHAPTER 10 TIME BASE TIMER ...
Page 247: ...228 CHAPTER 11 WATCHDOG TIMER ...
Page 275: ...256 CHAPTER 12 16 BIT RELOAD TIMER ...
Page 373: ...354 CHAPTER 14 MULTI FUNCTIONAL TIMER ...
Page 485: ...466 CHAPTER 16 PWC Timer ...
Page 531: ...512 CHAPTER 17 UART ...
Page 559: ...540 CHAPTER 19 DELAYED INTERRUPT GENERATOR MODULE ...
Page 589: ...570 CHAPTER 20 8 10 BIT A D CONVERTER ...
Page 601: ...582 CHAPTER 21 ROM CORRECTION FUNCTION ...
Page 633: ...614 CHAPTER 23 512K 1024K BIT FLASH MEMORY ...
Page 645: ...626 CHAPTER 24 EXAMPLE OF F2 MC 16LX MB90F462 F462A F463A CONNECTION FOR SERIAL WRITING ...
Page 715: ...696 APPENDIX ...
Page 716: ...697 INDEX INDEX The index follows on the next page This is listed in alphabetic order ...
Page 739: ......