SH7136 datasheet(174/1160 Pages) RENESAS

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Section 7 User Break Controller (UBC)

Rev. 2.00 Sep. 10, 2008 Page 148 of 1130

REJ09B0402-0200

3. When data access (address only) is specified as a break condition:

The address of the instruction immediately after the instruction that matched the break

condition is saved in the stack. The instruction that matches the condition is executed, and the

user break occurs before the next instruction is executed. However when a delay slot

instruction matches the condition, the branch destination address is saved in the stack.

4. When data access (address + data) is specified as a break condition:

When a data value is added to the break conditions, the address of an instruction that is within

two instructions of the instruction that matched the break condition is saved in the stack. At

which instruction the user break occurs cannot be determined accurately.

When a delay slot instruction matches the condition, the branch destination address is saved in

the stack. If the instruction following the instruction that matches the break condition is a

branch instruction, the break may occur after the branch instruction or delay slot has finished.

In this case, the branch destination address is saved in the stack.

7.4.6

PC Trace

1. Setting PCTE in BRCR to 1 enables PC traces. When branch (branch instruction, and interrupt

exception) is generated, the branch source address and branch destination address are stored in

BRSR and BRDR, respectively.

2. The values stored in BRSR and BRDR are as given below due to the kind of branch.

 If a branch occurs due to a branch instruction, the address of the branch instruction is saved

in BRSR and the address of the branch destination instruction is saved in BRDR.

 If a branch occurs due to an interrupt or exception, the value saved in stack due to

exception occurrence is saved in BRSR and the start address of the exception handling

routine is saved in BRDR.

3. BRSR and BRDR have four pairs of queue structures. The top of queues is read first when the

address stored in the PC trace register is read. BRSR and BRDR share the read pointer. Read

BRSR and BRDR in order, the queue only shifts after BRDR is read. After switching the

PCTE bit (in BRCR) off and on, the values in the queues are invalid.

4. Since four pairs of queue are shared with the AUD, set the PCTE bit in BRCR to 1 after setting

the MSTP25 bit in STBCR5 to 0 and the AUDSRST bit in STBCR6 to 1. This setting is

necessary even though this LSI does not have the AUD function.

5. A status of FIFO is initialized by a power-on reset, manual reset, or AUD software reset. When

the status of FIFO is initialized by a manual reset or an AUD software reset, clear the PCTE bit

in the BRCR register to 0 once, set the PCTE bit to 1, and then the PC trace can start.

SH7136 Datasheet(PDF) 174 Page - Renesas Technology Corp