tmp1941af TOSHIBA Semiconductor CORPORATION, tmp1941af Datasheet - Page 350

• Manufacturer Part Number: tmp1941af
• Description: 32-bit Tx System Risc
• Manufacturer: TOSHIBA Semiconductor CORPORATION

Overflow Exception #2
Problem:
If an overflow exception caused a jump to the exception handler and the first instruction in that exception
handler caused another exception, the EPC register should point to the address of the first instruction in the
exception handler. However, the EPC register might contain the address that caused the overflow
exception.
•
Note:
Workaround:
Don’t place a jump or branch instruction immediately following an instruction that could cause an
overflow (ADD, ADDI or SUB).
Problem-Causing Situation:
When, with the instruction pipeline full, an overflow exception was taken at the following
sequence of instructions and then the first instruction in the overflow exception handler causes
another exception
Toshiba’s compiler uses no instructions that could cause an overflow. Therefore, this
problem does not occur.
ADD, ADDI or SUB
Jump or branch instruction <= # Instruction with a delay slot
Delay slot
TMP1941AF-310
<= # Instruction that causes an overflow
TMP1941AF
2003-03-27