Renesas SH7041 Series, Hardware Manual, Page: 169 / 923

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Instruction execution: TRAPA instruction execution
→
Branch destination instruction
execution
3. Conditional delay branch instruction, branch taken: BT/S, BF/S
Instruction fetch cycles: Conditional delay branch instruction fetch
→
Next-instruction
fetch (delay slot)
→
Next-instruction overrun fetch
→
Branch destination instruction
fetch
Instruction execution: Conditional delay branch instruction execution
→
Delay slot
instruction execution
→
Branch destination instruction execution
When a conditional branch instruction or TRAPA instruction causes a branch, the branch
destination will be fetched after the next instruction or the one after that does an overrun fetch.
However, because the instruction that is the object of the break first breaks after a definite
instruction fetch and execution, the kind of overrun fetch instructions noted above do not
become objects of a break. If data access breaks are also included with instruction fetch breaks
as break conditions, a break occurs because the instruction overrun fetch is also regarded as
becoming a data break.
7.5.3 Contention between User Break and Exception Handling
If a user break is set for the fetch of a particular instruction, and exception handling with higher
priority than a user break is in contention and is accepted in the decode stage for that instruction
(or the next instruction), user break exception handling may not be performed after completion of
the higher-priority exception handling routine (on return by RTE).
Thus, if a user break condition has been set for the fetch of the branch destination instruction
following a branch (BRA, BRAF, BT, BF, BT/S, BF/S, BSR, BSRF, JMP, JSR, RTS, RTE,
exception handling), and exception handling for this branch destination instruction with a higher
priority than a user break interrupt is accepted, user break exception handling will not be
performed after completion of that exception handling routine.
Therefore, a user break condition must not be set for the fetch of the branch destination instruction
following a branch.
7.5.4 Break at Non-Delay Branch Instruction Jump Destination
When a branch instruction with no delay slot (including exception handling) jumps to the jump
destination instruction on execution of the branch, a user break will not be generated even if a user
break condition has been set for the first jump destination instruction fetch.