Rev. 1.0, 02/00, page 540 of 1141
4. When the condition is not satisfied by Bcc instruction (Trap address at branch)
When the trap address is at the branch of the Bcc instruction and the condition is not satisfied
by the Bcc instruction and thus it fails to branch, transition is made into the address trap
interrupt after executing the next instruction (if the next instruction is that of 2 states or more.
If the next instruction is that of 1 state, after executing two instructions). The address to be
stacked is 0262.
φ
Address bus
Interrupt
request
signal
Start of
exception
handling
025C
0262
0266
025E
0260
0264
025C BEQ NEXT:8
025E NOP
0260 NOP
0262 NOP
0264 NOP
0266 CMP.W R0, R1
0268 NOP
(NEXT = H'0266)
BEQ
execution
NOP
execu-
tion
NOP
execu-
tion
*
BEQ
instruc-
tion
pre-fetch
NOP
instruc-
tion
pre-fetch
NOP
instruc-
tion
pre-fetch
NOP
instruc-
tion
pre-fetch
CMP
instruc-
tion
pre-fetch
NEXT:
Note:
*
Trap setting address
The underlines address is the one to be actually stacked.
Figure 25.9 When the Condition Not Satisfied by Bcc Instruction
(Trap Address at Branch)