
270
CHAPTER 12 INTERRUPT CONTROLLER
12.6 Hold-Request Cancellation Request
To handle an interrupt with a higher priority while the CPU is in hold status, the
requester of the hold request must cancel that request. The interrupt level used to
determine whether a hold-request cancellation request is issued needs to be set in the
HRCL register.
■
Criteria for determining whether a hold-request cancellation-request must be issued
If an interrupt source with an interrupt level higher than that specified in the HRCL register is
issued, a hold-request cancellation request must be generated.
•
Interrupt level of HRCL register is greater than Interrupt level after evaluating priority
--> Cancellation request issued
•
Interrupt level of HRCL register is equal to or less than Interrupt level after evaluating priority
--> Cancellation request not issued
Since this cancellation request is valid unless the interrupt source is cleared, DMA transfer does
never start. Be sure to clear the corresponding interrupt source.
■
Levels that can be set for hold request cancellation requests
A number from 0000
B
to 1111
B
can be set in the HRCL register.
When 1111
B
is set, the cancellation request is issued for all interrupt levels. When 0000
B
is set,
the cancellation request is issued only for NMI.
Table 12.6-1 "Interrupt levels for which the hold-request cancellation request is issued" lists the
interrupt levels for which the hold-request cancellation request is issued.
Note:
After a reset, DMA transfer is disabled for all interrupt levels. This means that DMA transfer
is not performed when an interrupt has been issued. Therefore, set the HRCL register to the
appropriate value.
Table 12.6-1 Interrupt levels for which the hold-request cancellation request is issued
HRCL register
Interrupt levels for which the hold-request cancellation
request is issued
16
(Only NMI)
17
Interrupt level 16
18
Interrupt levels 16 to17
:
:
31
Interrupt levels 16-30 [initial value]
Summary of Contents for MB91150 Series
Page 1: ......
Page 2: ......
Page 3: ...FUJITSU LIMITED FR30 32 BIT MICROCONTROLLER MB91150 Series HARDWARE MANUAL ...
Page 4: ......
Page 10: ...vi ...
Page 112: ...96 CHAPTER 3 MEMORY SPACE CPU AND CONTROL UNIT ...
Page 178: ...162 CHAPTER 5 I O PORTS ...
Page 214: ...198 CHAPTER 7 16 BIT RELOAD TIMER ...
Page 240: ...224 CHAPTER 8 PPG TIMER ...
Page 310: ...294 CHAPTER 13 8 10 BIT A D CONVERTER ...
Page 318: ...302 CHAPTER 14 8 BIT D A CONVERTER ...
Page 362: ...346 CHAPTER 15 UART ...
Page 420: ...404 CHAPTER 19 PERIPHERAL STOP CONTROL ...
Page 428: ...412 CHAPTER 20 CALENDAR MACROS ...
Page 503: ...487 INDEX INDEX The index follows on the next page This is listed in alphabetic order ...
Page 510: ...494 INDEX ...
Page 512: ......