
Development Support
Background Debug Mode (BDM)
MC68HC912B32 MC68HC12BE32 — Rev. 3.0
Advance Information
MOTOROLA
Development Support
383
17.4.5.2 Firmware Command
The bits in the BDM instruction register have these meanings when a
firmware
command is executed.
H/F — Hardware/Firmware Flag
0 = Firmware control logic
1 = Hardware control logic
DATA — Data Flag
0 = No data
1 = Data included in command
R/W — Read/Write Flag
0 = Write
1 = Read
TTAGO — Trace, Tag, Go Field
Address: $FF00
Bit 7
6
5
4
3
2
1
Bit 0
Read:
H/F
DATA
R/W
TTAGO
REGN
Write:
Reset:
0
0
0
0
0
0
0
0
Figure 17-5. BDM Instruction Register (INSTRUCTION)
Table 17-5. TTAGO Decoding
TTAGO Value
Instruction
00
—
01
GO
10
TRACE1
11
TAGGO