Version 1 ColdFire Debug (CF1_DEBUG)
MCF51CN128 Reference Manual, Rev. 6
Freescale Semiconductor
20-33
Figure 20-18. BDM Target-to-Host Serial Bit Timing (Logic 0)
20.4.1.4
BDM Command Set Descriptions
This section presents detailed descriptions of the BDM commands.
The V1 BDM command set is based on transmission of one or more 8-bit data packets per operation. Each
operation begins with a host-to-target transmission of an 8-bit command code packet. The command code
definition broadly maps the operations into four formats as shown in
10 CYCLES
BDC CLOCK
(TARGET MCU)
HOST DRIVE
TO BKGD PIN
TARGET MCU
DRIVE AND
PERCEIVED START
OF BIT TIME
HIGH-IMPEDANCE
BKGD PIN
10 CYCLES
SPEED-UP PULSE
SPEEDUP
PULSE
EARLIEST START
OF NEXT BIT
HOST SAMPLES BKGD PIN