SH7670 Datasheet, PDF (1103/1292 Pages) Renesas Technology Corp – 32-Bit RISC Microcomputer SuperHTM RISC engine Family / SH7670 Series

Section 25 User Break Controller (UBC)
25.3.4 Value of Saved Program Counter
When a user break interrupt request is received, the address of the instruction from where
execution is to be resumed is saved to the stack, and the exception handling state is entered. If the
C bus (FAB)/instruction fetch cycle is specified as a break condition, the instruction at which the
break should occur can be uniquely determined. If the C bus/data access cycle or I bus/data access
cycle is specified as a break condition, the instruction at which the break should occur cannot be
uniquely determined.
1. When C bus (FAB)/instruction fetch (before instruction execution) is specified as a break
condition:
The address of the instruction that matched the break condition is saved to the stack. The
instruction that matched the condition is not executed, and the break occurs before it. However
when a delay slot instruction matches the condition, the instruction is executed, and the branch
destination address is saved to the stack.
2. When C bus (FAB)/instruction fetch (after instruction execution) is specified as a break
condition:
The address of the instruction following the instruction that matched the break condition is
saved to the stack. The instruction that matches the condition is executed, and the break occurs
before the next instruction is executed. However when a delayed branch instruction or delay
slot matches the condition, the instruction is executed, and the branch destination address is
saved to the stack.
3. When C bus/data access cycle or I bus/data access cycle is specified as a break condition:
The address after executing several instructions of the instruction that matched the break
condition is saved to the stack.
Rev. 1.00 Nov. 14, 2007 Page 1077 of 1262
REJ09B0437-0100