XC912BC32CFU8 Motorola Semiconductor Products, XC912BC32CFU8 Datasheet - Page 325

• Manufacturer Part Number: XC912BC32CFU8
• Description: M68HC12B Family Data Sheet
• Manufacturer: Motorola Semiconductor Products

18.3.6 BDM Status Register
M68HC12B Family — Rev. 8.0
MOTOROLA
Single-Chip Peripheral:
This register can be read or written by BDM commands or firmware.
ENBDM — Enable BDM Bit (permit active background debug mode)
BDMACT — Background Mode Active Status Bit
ENTAG — Instruction Tagging Enable Bit
SDV — Shifter Data Valid Bit
TRACE
Set by the TAGGO instruction and cleared when BDM is entered.
Shows that valid data is in the serial interface shift register. Used by
firmware-based instructions.
Asserted by the TRACE1 instruction
Address: $FF01
Reset:
Read:
Write:
0 = BDM cannot be made active (hardware commands still allowed).
1 = BDM can be made active to allow firmware commands.
0 = BDM not active
1 = BDM active and waiting for serial commands
0 = Tagging not enabled, or BDM active
1 = Tagging active (BDM cannot process serial commands while tagging is
0 = No valid data
1 = Valid data
active.)
ENBDM
Bit 7
Figure 18-6. BDM Status Register (STATUS)
0
1
EDMACT
Development Support
6
0
0
ENTAG
5
0
0
SDV
4
0
0
TRACE
3
0
0
Background Debug Mode (BDM)
2
0
0
0
Development Support
1
0
0
0
Data Sheet
Bit 0
0
0
0
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