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CHAPTER 3 MEMORY SPACE, CPU AND CONTROL UNIT
3.8.5
EIT Operation
This section describes EIT operation.
Assume that the PC of the transfer source in the explanation below indicates the
address of the instruction for which an EIT source was detected.
"Address of the next instruction" means that the instruction for which EIT was
detected satisfies the following conditions:
• LDI:32: PC + 6
• LDI:20, COPOP, COPLD, COPST, and COPSV: PC + 4
• Other instructions: PC + 2
■
User interrupt operation
If a user interrupt request occurs, the system determines whether the request can be accepted
in the following order:
❍
Determination of whether the interrupt request can be accepted
1. The interrupt levels of concurrent requests are compared with each other. The request with
the highest level (smallest value) is selected. For an interrupt that can be masked, the value
stored by the associated ICR is used as the level for comparison.
2. If two or more interrupt requests with the same level occur, the interrupt request having the
smallest number is selected.
3. The interrupt level of the selected interrupt request is compared with the level mask value
determined by the ILM.
•
In case the interrupt level is equal to or greater than the level mask value, the interrupt
request is masked and is not accepted.
•
If the interrupt level is smaller than the level mask value, the system proceeds with step 4.
4. When the selected interrupt request can be masked and the I flag is 0, the interrupt request
is masked and is not accepted.
•
If the I flag is 1, the system proceeds with step 5.
5. When the above condition is met, the interrupt request is accepted at a pause of instruction
processing.
❍
Operation
When a user interrupt request is accepted at EIT request detection, the CPU operates as shown
below while using the interrupt number associated with the accepted interrupt request.
The items in parentheses in 1. to 7. below show the address indicated by the register.
1. SSP-4 --> SSP
2. PS --> (SSP)
3. SSP-4 --> SSP
4. Address of the next instruction --> (SSP)
5. Interrupt level of the accepted request --> ILM
Summary of Contents for MB91150 Series
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Page 2: ......
Page 3: ...FUJITSU LIMITED FR30 32 BIT MICROCONTROLLER MB91150 Series HARDWARE MANUAL ...
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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 ...
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