M68HC12A4EVB Freescale Semiconductor, M68HC12A4EVB Datasheet - Page 298

• Manufacturer Part Number: M68HC12A4EVB
• Manufacturer: Freescale Semiconductor

Specifications of M68HC12A4EVB

• Lead Free Status / Rohs Status: Not Compliant

Development Support
18.3.6 BDM Status Register
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
18.3.7 BDM Shifter Register
The 16-bit SHIFTER register contains data being received or transmitted via the serial interface. It is also
used by the BDM firmware for temporary storage. The register can be read or written in all modes but is
not normally accessed by users.
298
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
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 active.)
0 = No valid data
1 = Valid data
Single-Chip Peripheral:
Reset:
Address: $FF02
Address: $FF03
Read:
Write:
Reset:
Read:
Write:
Address: $FF01
Reset:
Read:
Write:
Bit 7
Bit 7
S15
S7
0
0
ENBDM
Bit 7
Figure 18-7. BDM Shifter Register (SHIFTER)
Figure 18-6. BDM Status Register (STATUS)
0
1
S14
S6
6
0
6
0
EDMACT
M68HC12B Family Data Sheet, Rev. 9.1
6
0
0
S13
S5
5
0
5
0
ENTAG
5
0
0
S12
S4
4
0
4
0
SDV
4
0
0
S11
S3
3
0
3
0
TRACE
3
0
0
S10
S2
2
0
2
0
2
0
0
0
S9
S1
1
0
1
0
1
0
0
0
Freescale Semiconductor
Bit 0
Bit 0
S8
S0
0
0
Bit 0
0
0
0