mc9s08qg4 Freescale Semiconductor, Inc, mc9s08qg4 Datasheet - Page 252

• Manufacturer Part Number: mc9s08qg4
• Description: Hcs08 Microcontrollers Microcontroller Family
• Manufacturer: Freescale Semiconductor, Inc

Chapter 17 Development Support
17.2.3
BDC commands are sent serially from a host computer to the BKGD pin of the target HCS08 MCU. All
commands and data are sent MSB-first using a custom BDC communications protocol. Active background
mode commands require that the target MCU is currently in the active background mode while
non-intrusive commands may be issued at any time whether the target MCU is in active background mode
or running a user application program.
Table 17-1
meaning of each command.
Coding Structure Nomenclature
This nomenclature is used in
252
AAAA
WBKP
WD16
RBKP
RD16
WD
RD
CC
SS
d
/
shows all HCS08 BDC commands, a shorthand description of their coding structure, and the
BDC Commands
=
=
=
=
=
=
=
=
=
=
=
Commands begin with an 8-bit hexadecimal command code in the host-to-target
direction (most significant bit first)
separates parts of the command
delay 16 target BDC clock cycles
a 16-bit address in the host-to-target direction
8 bits of read data in the target-to-host direction
8 bits of write data in the host-to-target direction
16 bits of read data in the target-to-host direction
16 bits of write data in the host-to-target direction
the contents of BDCSCR in the target-to-host direction (STATUS)
8 bits of write data for BDCSCR in the host-to-target direction (CONTROL)
16 bits of read data in the target-to-host direction (from BDCBKPT breakpoint
register)
16 bits of write data in the host-to-target direction (for BDCBKPT breakpoint register)
Table 17-1
MC9S08QG8 and MC9S08QG4 Data Sheet, Rev. 4
to describe the coding structure of the BDC commands.
Freescale Semiconductor