CHAPTER 17 INTERRUPT/EXCEPTION PROCESSING FUNCTION
User’s Manual U16896EJ2V0UD
564
17.6.2 Debug trap
A debug trap is an exception that occurs upon execution of the DBTRAP instruction and that can be acknowledged
at all times.
When a debug trap occurs, the CPU performs the following processing.
(1) Operation
<1> Saves the restored PC to DBPC.
<2> Saves the current PSW to DBPSW.
<3> Sets the PSW.NP, PSW.EP, and PSW.ID bits to 1.
<4> Sets the handler address (00000060H) for the debug trap routine to the PC and transfers control.
Figure 17-12 shows the debug trap processing flow.
Figure 17-12. Debug Trap Processing
DBTRAP instruction
DBPC
DBPSW
PSW.NP
PSW.EP
PSW.ID
PC
Restored PC
PSW
1
1
1
00000060H
Debug monitor routine processing
CPU processing