M68HC12A4EVB Freescale Semiconductor, M68HC12A4EVB Datasheet - Page 297

• Manufacturer Part Number: M68HC12A4EVB
• Manufacturer: Freescale Semiconductor

Specifications of M68HC12A4EVB

• Lead Free Status / Rohs Status: Not Compliant

18.3.5.2 Firmware Command
The bits in the BDM instruction register have these meanings when a firmware command is executed.
H/F — Hardware/Firmware Flag
DATA — Data Flag
R/W — Read/Write Flag
TTAGO — Trace, Tag, Go Field
REGN — Register/Next Field
Freescale Semiconductor
Indicates which register is being affected by a command. In the case of a READ_NEXT or
WRITE_NEXT command, index register X is pre-incremented by two and the word pointed to by X is
then read or written.
0 = Firmware control logic
1 = Hardware control logic
0 = No data
1 = Data included in command
0 = Write
1 = Read
Address: $FF00
Reset:
Read:
Write:
Figure 18-5. BDM Instruction Register (INSTRUCTION)
Bit 7
H/F
0
TTAGO Value
TTAGO Value
DATA
6
0
M68HC12B Family Data Sheet, Rev. 9.1
000
001
010
011
00
01
10
11
Table 18-5. TTAGO Decoding
Table 18-6. REGN Decoding
R/W
5
0
4
0
TTAGO
READ/WRITE NEXT
3
0
Instruction
Instruction
TRACE1
TAGGO
GO
PC
—
—
—
2
0
Background Debug Mode (BDM)
REGN
1
0
Bit 0
0
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