
Section 2 Software Specifications when Using the SH7781
Rev. 2.00 Jan. 28, 2008 Page 16 of 32
REJ10J1422-0200
2.2.3 Notes on Setting the [Breakpoint] Dialog Box
1. When an odd address is set, the next lowest even address is used.
2. A BREAKPOINT is accomplished by replacing instructions of the specified address.
Accordingly, it can be set only to the internal RAM area. However, a BREAKPOINT cannot
be set to the following addresses:
⎯ ROM areas in CS0 to CS6
⎯ Areas other than CS0 to CS6
⎯ Areas other than the internal RAM
⎯ A slot instruction of a delayed branch instruction
⎯ An area that can be only read by MMU
3. During step operation, BREAKPOINTs are disabled.
4. When execution resumes from the address where a BREAKPOINT is specified, single-step
operation is performed at the address and execution is continued from the next PC value.
Therefore, realtime operation cannot be performed.
5. When a BREAKPOINT is set to the slot instruction of a delayed branch instruction, the PC
value becomes an illegal value. Accordingly, do not set a BREAKPOINT to the slot
instruction of a delayed branch instruction.
6. Note on DSP repeat loop:
A BREAKPOINT is equal to a branch instruction. In some DSP repeat loops, branch
instructions cannot be set. For these cases, do not set BREAKPOINTs. Refer to the hardware
manual for details.
7. When the [Normal] option is selected in the [Memory area] group box in the [General] page of
the [Configuration] dialog box, a BREAKPOINT is set to a physical address or a virtual
address according to the SH7781 MMU status during command input when the VPMAP_SET
command setting is disabled. The ASID value of the SH7781 PTEH register during command
input is used. When VPMAP_SET command setting is enabled, a BREAKPOINT is set to a
physical address into which address translation is made according to the VP_MAP table.
However, for addresses out of the range of the VP_MAP table, the address to which a
BREAKPOINT is set depends on the SH7781 MMU status during command input. Even
when the VP_MAP table is modified after BREAKPOINT setting, the address translated when
the BREAKPOINT is set valid.
8. When the [Physical] option is selected in the [Memory area] group box in the [General] page
of the [Configuration] dialog box, a BREAKPOINT is set to a physical address. A
BREAKPOINT is set after disabling the SH7781 MMU upon program execution. After
setting, the MMU is returned to the original state. When a break occurs at the corresponding
virtual address, the cause of termination displayed in the status bar and the [Output] window is
ILLEGAL INSTRUCTION, not BREAKPOINT.
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