mc9s12xs128 Freescale Semiconductor, Inc, mc9s12xs128 Datasheet - Page 178

• Manufacturer Part Number: mc9s12xs128
• Description: Hcs12 Microcontrollers 16-bit Automotive Microcontroller
• Manufacturer: Freescale Semiconductor, Inc

Background Debug Module (S12XBDMV2)
5.4.4
Firmware commands are used to access and manipulate CPU resources. The system must be in active
BDM to execute standard BDM firmware commands, see
Normal instruction execution is suspended while the CPU executes the firmware located in the standard
BDM firmware lookup table. The hardware command BACKGROUND is the usual way to activate BDM.
As the system enters active BDM, the standard BDM firmware lookup table and BDM registers become
visible in the on-chip memory map at 0x7FFF00–0x7FFFFF, and the CPU begins executing the standard
BDM firmware. The standard BDM firmware watches for serial commands and executes them as they are
received.
The firmware commands are shown in
178
WRITE_WORD
NOTE:
If enabled, ACK will occur when data is ready for transmission for all BDM READ commands and will occur after the write is
complete for all BDM WRITE commands.
Command
Standard BDM Firmware Commands
Opcode
(hex)
C8
16-bit address
16-bit data in
Table 5-6. Hardware Commands (continued)
Data
S12XS Family Reference Manual, Rev. 1.10
Table
Write to memory with standard BDM firmware lookup table out of map.
Must be aligned access.
5-7.
Section 5.4.2, “Enabling and Activating
Description
Freescale Semiconductor
BDM”.