Debug Module
MCF52235 ColdFire® Integrated Microcontroller Reference Manual, Rev. 6
Freescale Semiconductor
31-5
Therefore, loading a register to perform a specific function that shares hardware resources is destructive
to the shared function. For example, if an operand address breakpoint is loaded into the debug module, a
BDM command to access memory overwrites an address breakpoint in ABHR. If a data breakpoint is
configured, a BDM write command overwrites the data breakpoint in DBR.
Revision B added hardware registers to eliminate these shared functions. The BAAR is used to specify bus
attributes for BDM memory commands and has the same format as the LSB of the AATR. The registers
containing the BDM memory address and the BDM data are not program visible.
31.3.2
Configuration/Status Register (CSR)
The CSR defines the debug configuration for the processor and memory subsystem and contains status
information from the breakpoint logic. CSR is write-only from the programming model. It can be read
from and written to through the BDM port. CSR is accessible in supervisor mode as debug control register
0x00 using the WDEBUG instruction and through the BDM port using the
RDMREG
and
WDMREG
commands.
Table 31-4. Shared BDM/Breakpoint Hardware
Register
BDM Function
Breakpoint Function
AATR
Bus attributes for all memory commands
Attributes for address breakpoint
ABHR
Address for all memory commands
Address for address breakpoint
DBR
Data for all BDM write commands
Data for data breakpoint
DRc[4:0]: 0x00 (CSR)
Access: Supervisor write-only
BDM read/write
31
30
29
28
27
26
25
24
23
22
21
20
19
18
17
16
R
BSTAT
FOF
TRG
HALT BKPT
HRL
0
BKD
PCD
IPW
W
Reset
0
0
0
0
0
0
0
0
1
0
0
1
0
0
0
0
15
14
13
12
11
10
9
8
7
6
5
4
3
2
1
0
R
MAP
TRC
EMU
DDC
UHE
BTB
0
NPL
IPI
SSM
0
0
FDBG DBGH
W
Reset
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
Figure 31-2. Configuration/Status Register (CSR)
Because
of
an
order
from
the
United
States
International
Trade
Commission,
BGA-packaged
product
lines
and
part
numbers
indicated
here
currently
are
not
available
from
Freescale
for
import
or
sale
in
the
United
States
prior
to
September
2010:MCF52234CVM60,
MCF52235CVM60
