Renesas SH7709S Stereo System User Manual


 
Rev. 5.00, 09/03, page 172 of 760
7.3.4 Sequential Break
1. By specifying SEQ in BRCR is set to 1, the sequential break is issued when channel B break
condition matches after channel A break condition matches. A user break is ignored even if
channel B break condition matches before channel A break condition matches. When channels
A and B condition match at the same time, the sequential break is not issued.
2. In sequential break specification, a logical bus or internal bus can be selected and the execution
times break condition can be also specified. For example, when the execution times break
condition is specified, the break condition is satisfied at channel B condition match with BETR
= H'0001 after channel A condition match.
7.3.5 Value of Saved Program Counter
The PC when a break occurs is saved to the SPC in user breaks. The PC value saved is as follows
depending on the type of break.
1. When instruction fetch (before instruction execution) is specified as a break condition:
The value of the program counter (PC) saved is the address of the instruction that matches the
break condition. The fetched instruction is not executed, and a break occurs before it.
2. When instruction fetch (after instruction execution) is specified as a break condition:
The PC value saved is the address of the instruction to be executed following the instruction in
which the break condition matches. The fetched instruction is executed, and a break occurs
before the execution of the next instruction.
3. When data access (address only) is specified as a break condition:
The PC value is the address of the instruction to be executed following the instruction that
matched the break condition. The instruction that matched the condition is executed and the
break occurs before the next instruction is executed.
4. When data access (address + data) is specified as a break condition:
The PC value is the start address of the instruction that follows the instruction already executed
when break processing started up. When a data value is added to the break conditions, the
place where the break will occur cannot be specified exactly. The break will occur before the
execution of an instruction fetched around the data access where the break occurred.