Chapter 8 S12X Debug (S12XDBGV3) Module
MC9S12XE-Family Reference Manual Rev. 1.19
Freescale Semiconductor
319
8.3.2.8
Comparator Register Descriptions
Each comparator has a bank of registers that are visible through an 8-byte window in the S12XDBG
module register address map. Comparators A and C consist of 8 register bytes (3 address bus compare
registers, two data bus compare registers, two data bus mask registers and a control register).
Comparators B and D consist of four register bytes (three address bus compare registers and a control
register).
Each set of comparator registers is accessible in the same 8-byte window of the register address map and
can be accessed using the COMRV bits in the DBGC1 register. If the Comparators B or D are accessed
through the 8-byte window, then only the address and control bytes are visible, the 4 bytes associated with
data bus and data bus masking read as zero and cannot be written. Furthermore the control registers for
comparators B and D differ from those of comparators A and C.
8.3.2.8.1
Debug Comparator Control Register (DBGXCTL)
The contents of this register bits 7 and 6 differ depending upon which comparator registers are visible in
the 8-byte window of the DBG module register address map.
Read: Anytime. See
for visible register encoding.
Table 8-28. Comparator Register Layout
0x0028
CONTROL
Read/Write
Comparators A,B,C,D
0x0029
ADDRESS HIGH
Read/Write
Comparators A,B,C,D
0x002A
ADDRESS MEDIUM
Read/Write
Comparators A,B,C,D
0x002B
ADDRESS LOW
Read/Write
Comparators A,B,C,D
0x002C
DATA HIGH COMPARATOR
Read/Write
Comparator A and C only
0x002D
DATA LOW COMPARATOR
Read/Write
Comparator A and C only
0x002E
DATA HIGH MASK
Read/Write
Comparator A and C only
0x002F
DATA LOW MASK
Read/Write
Comparator A and C only
Address: 0x0028
7
6
5
4
3
2
1
0
R
0
NDB
TAG
BRK
RW
RWE
SRC
COMPE
W
Reset
0
0
0
0
0
0
0
0
= Unimplemented or Reserved
Figure 8-13. Debug Comparator Control Register (Comparators A and C)
Address: 0x0028
7
6
5
4
3
2
1
0
R
SZE
SZ
TAG
BRK
RW
RWE
SRC
COMPE
W
Reset
0
0
0
0
0
0
0
0
Figure 8-14. Debug Comparator Control Register (Comparators B and D)
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:
S12XE
products
in
208
MAPBGA
packages
