7 resume execution (go), 8 no operation (nop), 9 read control register (rcreg) – Motorola ColdFire MCF5281 User Manual
Page 649: 7 resume execution, Command sequence
Debug Support
Freescale Semiconductor
30-31
30.5.3.3.7
Resume Execution (
GO
)
The pipeline is flushed and refilled before normal instruction execution resumes. Prefetching begins at the
current address in the PC and at the current privilege level. If any register (such as the PC or SR) is altered
by a BDM command while the processor is halted, the updated value is used when prefetching resumes.
If a
GO
command is issued and the CPU is not halted, the command is ignored.
Command Sequence:
Figure 30-30.
GO
Command Sequence
Operand Data:
None
Result Data:
The command-complete response (0xFFFF) is returned during the next shift
operation.
30.5.3.3.8
No Operation (
NOP
)
NOP
performs no operation and may be used as a null command where required.
Command Formats:
Command Sequence:
Figure 30-32.
NOP
Command Sequence
Operand Data:
None
Result Data:
The command-complete response, 0xFFFF (with S cleared), is returned during the
next shift operation.
30.5.3.3.9
Read Control Register (
RCREG
)
Reads the selected control register and returns the 32-bit result. Accesses to the processor/memory control
registers are always 32 bits wide, regardless of register width. The second and third words of the command
form a 32-bit address, which the debug module uses to generate a special bus cycle to access the specified
control register. The 12-bit Rc field is the same as that used by the MOVEC instruction.
15
12
11
8
7
4
3
0
0x0
0xC
0x0
0x0
Figure 30-29.
GO
Command Format
15
12
11
8
7
4
3
0
0x0
0x0
0x0
0x0
Figure 30-31.
NOP
Command Format
GO
???
NEXT CMD
’CMD COMPLETE’
NOP
???
NEXT CMD
’CMD COMPLETE’
MCF5282 and MCF5216 ColdFire Microcontroller User’s Manual, Rev. 3