7.1.2.4 Exception exit
(1)
Execution after returning from an ISR
When returning from an ISR, the CPU takes one of the following actions:
・
Tail-chaining
If a pending exception exists and there are no stacked exceptions or the pending excep-
tion has higher priority than all stacked exceptions, the CPU returns to the ISR of the pend-
ing exception.
In this case, the CPU skips the pop of eight registers and push of eight registers when ex-
iting one ISR and entering another. This is called "tail-chaining".
・
Returning to the last stacked ISR
If there are no pending exceptions or if the highest priority stacked exception is of high-
er priority than the highest priority pending exception, the CPU returns to the last stacked
ISR.
・
Returning to the previous program
If there are no pending or stacked exceptions, the CPU returns to the previous program.
(2)
Exception exit sequence
When returning from an ISR, the CPU performs the following operations:
・
Pop eight registers
Pops the eight registers (PC, xPSR, r0 to r3, r12 and LR) from the stack and adjust the
SP.
・
Load current active interrupt number
Loads the current active interrupt number from the stacked xPSR. The CPU uses this to
track which interrupt to return to.
・
Select SP
If returning to an exception (Handler Mode), SP is SP_main. If returning to Thread
Mode, SP can be SP_main or SP_process.
TMPM3V6/M3V4
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Summary of Contents for TMPM3V4
Page 1: ...32 Bit RISC Microcontroller TX03 Series TMPM3V6 M3V4 ...
Page 2: ... 2019 Toshiba Electronic Devices Storage Corporation ...
Page 7: ...Revision History Date Revision Comment 2019 02 06 1 First Release ...
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Page 52: ...TMPM3V6 M3V4 3 Processor Core 3 6 Exclusive access Page 30 2019 02 06 ...
Page 148: ...TMPM3V6 M3V4 7 Exceptions 7 6 Exception Interrupt Related Registers Page 126 2019 02 06 ...
Page 178: ...TMPM3V6 M3V4 9 Input Output port 9 2 Block Diagrams of Ports Page 156 2019 02 06 ...
Page 354: ...TMPM3V6 M3V4 14 Synchronous Serial Port SSP 14 6 Frame Format Page 332 2019 02 06 ...
Page 419: ...TMPM3V6 M3V4 Page 397 2019 02 06 ...
Page 462: ...TMPM3V6 M3V4 21 Watchdog Timer WDT 21 5 Control register Page 440 2019 02 06 ...
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