238
CHAPTER 8 INTERRUPT CONTROLLER
Example of interrupt routines
The above example indicates that a priority interrupt is caused during execution of interrupt
routine I. In this case, incrementing PDRR at the beginning of each interrupt routine and
decrementing it at the exit of each routine can also prevent a hold request from being issued
accidentally.
<Notes>
•
Always increment PDRR at the beginning of the interrupt routine to be executed during DMA
transfer (in CPU hold state) and decrement it at the exit of the routine to prevent DMA
transfer during execution of the interrupt routine.
•
On the other hand, incrementing or decrementing PDRR during execution of an ordinary
interrupt routine prevents DMA transfer during execution of the interrupt routine and may
deteriorate performance.
•
Carefully note the relationship between the interrupt levels set in the HRCL and the ICR
registers.
Incrementing PDRR
Clearing the interrupt cause
Decrementing PDRR
RETI
Summary of Contents for MB91F109
Page 2: ......
Page 3: ...FUJITSU LIMITED FR30 32 Bit Microcontroller MB91F109 Hardware Manual ...
Page 4: ......
Page 10: ...vi ...
Page 24: ...xx ...
Page 96: ...72 CHAPTER 2 CPU ...
Page 224: ...200 CHAPTER 4 BUS INTERFACE ...
Page 234: ...210 CHAPTER 5 I O PORTS ...
Page 268: ...244 CHAPTER 9 U TIMER ...
Page 290: ...266 CHAPTER 10 UART ...
Page 314: ...290 CHAPTER 12 16 BIT RELOAD TIMER ...
Page 322: ...298 CHAPTER 13 BIT SEARCH MODULE ...
Page 392: ...368 CHAPTER 16 FLASH MEMORY ...
Page 432: ...408 APPENDIX E Instructions F Table E 2 Instruction Formats OP rel11 5 11 ...
Page 448: ...424 APPENDIX E Instructions ...
Page 449: ...425 INDEX INDEX The index follows on the next page This is listed in alphabetic order ...
Page 458: ...434 INDEX ...
Page 460: ......
Page 461: ...FUJITSU SEMICONDUCTOR FR30 32 Bit Microcontroller MB91F109 Hardware Manual ...