MC68HC812A4 Datasheet, PDF (317/342 Pages) Motorola, Inc – 16-bit device composed of standard on-chip peripheral modules connected by an intermodule bus. Modules include

Development Support
BDM Registers
17.5.2 BDM Status Register
Address: $FF01
Bit 7
6
5
4
3
2
Read:
ENBDM EDMACT ENTAG SDV TRACE
0
Write:
Reset: 0
0
0
0
0
0
Single-chip peripheral: 1
0
0
0
0
0
Figure 17-6. BDM Status Register (STATUS)
1
Bit 0
0
0
0
0
0
0
This register can be read or written by BDM commands or firmware.
ENBDM — Enable BDM Bit (permit active background debug mode)
1 = BDM can be made active to allow firmware commands
0 = BDM cannot be made active (hardware commands still
allowed).
BDMACT — Background Mode Active Status Bit
1 = BDM active and waiting for serial commands
0 = BDM not active
ENTAG — Instruction Tagging Enable Bit
Set by the TAGGO instruction and cleared when BDM is entered.
1 = Tagging active (BDM cannot process serial commands while
tagging is active.)
0 = Tagging not enabled or BDM active
SDV — Shifter Data Valid Bit
Shows that valid data is in the serial interface shift register. Used by
firmware-based instructions.
1 = Valid data
0 = No valid data
TRACE — Asserted by the TRACE1 Instruction
Advance Information
MOTOROLA
Development Support
MC68HC812A4 — Rev. 3.0
317