5
5-17
Ver.0.10
5.5 Description of Interrupt Operation
5.5.1 Acceptance of Internal Peripheral I/O Interrupts
An interrupt from any internal peripheral I/O is checked to see whether or not to accept by
comparing its ILEVEL value set by the Interrupt Control Register and the IMASK value of the
Interrupt Mask Register. If its priority is higher than the IMASK value, the interrupt is accepted.
However, when multiple interrupt requests occur simultaneously, the interrupt controller resolves
priority between these interrupt requests following the procedure described below.
➀
The ILEVEL values set by the Interrupt Control Register for each interrupt peripheral I/O are
compared with each other.
➁
If the ILEVEL values are the same, they are resolved according to the predetermined
hardware priority.
➂
The ILEVEL value is compared with IMASK value.
When multiple interrupt requests occur simultaneously, the interrupt controller first compares their
priority levels set by each Interrupt Control Register's ILEVEL bit to select an interrupt request
which has the highest priority. If the interrupt requests have the same LEVEL value, they are
resolved according to the hardware-fixed priority.
The interrupt request thus selected has its ILEVEL value compared with IMASK value and if its
priority is higher than the IMASK value, the interrupt controller sends an EI request to the CPU.
Interrupt requests may be masked by setting the Interrupt Mask Register and the Interrupt Control
Register's ILEVEL bit (level 7 = disabled) provided for each internal peripheral I/O and the PSW
register IE bit.
Figure 5.5.1 Example of Priority Resolution When Accepting Interrupt
Interrupt
requested
or not
Resolve priority
according to
interrupt priority
levels (ILEVEL)
Resolve priority
according to
hardware priority
Compare with
IMASK value
MJT Output Interrupt 4
MJT Output Interrupt 3
MJT Output Interrupt 2
MJT Output Interrupt 1
DMA0-4 Interrupt
A-D0 Converter Interrupt
(ILEVEL settings)
Level 3
Level 4
Level 5
Level 3
Level 1
Level 3
Not requested
Requested
Requested
Requested
Requested
Requested
Hardware-fixed
priority
Accept interrupt if
PSW register IE bit
= 1
Level 3
Level 3
Level 3
1
2
3
Can be accepted when
IMASK = 4-7
INTERRUPT CONTROLLER (ICU)
5.5 Description of Interrupt Operation
Summary of Contents for M32170F3VFP
Page 42: ...1 1 24 Ver 0 10 OVERVIEW 1 4 Pin Layout This is a blank page ...
Page 56: ...2 2 14 Ver 0 10 This is a blank page ...
Page 88: ...3 3 32 Ver 0 10 ADDRESS SPACE 3 7 Notes on Address Space This is a blank page ...
Page 270: ...9 9 40 Ver 0 10 DMAC 9 4 Precautions about the DMAC This is a blank page ...
Page 614: ...12 12 64 Ver 0 10 This is a blank page SERIAL I O 12 9 Precautions on Using UART Mode ...
Page 756: ...17 17 10 Ver 0 10 RAM BACKUP MODE 17 4 Exiting RAM Backup Mode Wakeup This is a blank page ...
Page 762: ...18 18 6 Ver 0 10 OSCILLATION CIRCUIT 18 2 Clock Generator Circuit This is a blank page ...
Page 831: ...CHAPTER 22 CHAPTER 22 TYPICAL CHARACTERISTICS 22 1 A D Conversion Characteristics ...
Page 833: ...Appendix 1 1 Dimensional Outline Drawing APPENDIX 1 APPENDIX 1 MECHANICAL SPECIFICATIONS ...
Page 841: ...Appendix 3 1 Precautions about Noise APPENDIX 3 APPENDIX 3 PRECAUTIONS ABOUT NOISE ...