Version 1 ColdFire Debug (CF1_DEBUG)
MCF51CN128 Reference Manual, Rev. 6
Freescale Semiconductor
20-27
Figure 20-15. PST Trace Buffer Entries and Locations
20.4
Functional Description
20.4.1
Background Debug Mode (BDM)
This section provides details on the background debug serial interface controller (BDC) and the BDM
command set.
The BDC provides a single-wire debug interface to the target MCU. As shown in the Version 1 ColdFire
core block diagram of
, the BDC module interfaces between the single-pin (BKGD) interface
and the remaining debug modules, including the ColdFire background debug logic, the real-time debug
hardware, and the PST/DDATA trace logic. This interface provides a convenient means for programming
the on-chip flash and other non-volatile memories. The BDC is the primary debug interface for
development and allows non-intrusive access to memory data and traditional debug features such as
run/halt control, read/write of core registers, breakpoints, and single instruction step.
Features of the background debug controller (BDC) include:
•
Single dedicated pin for mode selection and background communications
•
Special BDC registers not located in system memory map
•
SYNC command to determine target communications rate
•
Non-intrusive commands for memory access
•
Active background (halt) mode commands for core register access
•
GO command to resume execution
•
BACKGROUND command to halt core or wake CPU from low-power modes
•
Oscillator runs in stop mode, if BDM enabled
Core register
number (CRN)
31
30
29
28
27
26
25
24
23
22
21
20
19
18
17
16
15
14
13
12
11
10
9
8
7
6
5
4
3
2
1
0
0x10
TB #00
TB #01
TB #02
TB #03
TB #04
05[5:4]
0x11
TB #05[3:0]
TB #06
TB #07
TB #08
TB #09
TB #10[5:2]
0x12
10[1:0]
TB #11
TB #12
TB #13
TB #14
TB #15
0x13
TB #16
TB #17
TB #18
TB #19
TB #20
21[5:4]
0x14
TB #21[3:0]
TB #22
TB #23
TB #24
TB #25
TB #26[5:2]
0x15
26[1:0]
TB #27
TB #28
TB #29
TB #30
TB #31
0x16
TB #32
TB #33
TB #34
TB #35
TB #36
37[5:4]
0x17
TB #37[3:0]
TB #38
TB #39
TB #40
TB #41
TB #42[5:2]
0x18
42[1:0]
TB #43
TB #44
TB #45
TB #46
TB #47
0x19
TB #48
TB #49
TB #50
TB #51
TB #52
53[5:4]
0x1A
TB #53[3:0]
TB #54
TB #55
TB #56
TB #57
TB #58[5:2]
0x1B
58[1:0]
TB #59
TB #60
TB #61
TB #62
TB #63
