MC912D60ACPVE8 Datasheet, PDF (385/460 Pages) Freescale Semiconductor, Inc – MC68HC912D60A MC68HC912D60C MC68HC912D60P Technical Data

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Background Debug Mode
Command
READ_NEXT
READ_PC
READ_D
READ_X
READ_Y
READ_SP
WRITE_NEXT
WRITE_PC
WRITE_D
WRITE_X
WRITE_Y
WRITE_SP
GO
TRACE1
TAGGO
Table 19-3. BDM Firmware Commands
Opcode
(Hex)
62
63
64
65
66
67
42
43
44
45
46
47
08
10
18
Data
Description
16-bit data out
16-bit data out
16-bit data out
16-bit data out
16-bit data out
16-bit data out
16-bit data in
16-bit data in
16-bit data in
16-bit data in
16-bit data in
16-bit data in
None
None
None
X = X + 2; Read next word pointed to by X
Read program counter
Read D accumulator
Read X index register
Read Y index register
Read stack pointer
X = X + 2; Write next word pointed to by X
Write program counter
Write D accumulator
Write X index register
Write Y index register
Write stack pointer
Go to user program
Execute one user instruction then return to
BDM
Enable tagging and go to user program
Each of the hardware and firmware BDM commands start with an 8-bit
command code (opcode). Depending upon the commands, a 16-bit
address and/or a 16-bit data word is required as indicated in the tables
by the command. All the read commands output 16-bits of data despite
the byte/word implication in the command name.
The external host should wait 150 BDMCLK cycles for a non-intrusive
BDM command to execute before another command is sent. This delay
includes 128 BDMCLK cycles for the maximum delay for a free cycle.
For data read commands, the host must insert this delay between
sending the address and attempting to read the data. In the case of a
write command, the host must delay after the data portion before
sending a new command to be sure that the write has finished.
The external host should delay about 32 target BDMCLK cycles between
a firmware read command and the data portion of these commands. This
allows the BDM firmware to execute the instructions needed to get the
requested data into the BDM SHIFTER register.
MC68HC912D60A — Rev. 3.1
Freescale Semiconductor
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Technical Data
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