
Functional Description and Application Information
S12S Debug (S12SDBGV1) Module
MM912F634
Freescale Semiconductor
226
4.31.3.2.8.1
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: DBGACTL if COMRV[1:0] = 00
DBGBCTL if COMRV[1:0] = 01
DBGCCTL if COMRV[1:0] = 10
Write: DBGACTL if COMRV[1:0] = 00 and DBG not armed
DBGBCTL if COMRV[1:0] = 01 and DBG not armed
DBGCCTL if COMRV[1:0] = 10 and DBG not armed
Table 289. Debug Comparator Control Register DBGACTL (Comparator A)
Address: 0x0028
7
6
5
432
10
R0
NDB
TAG
BRK
RW
RWE
0
COMPE
W
Reset
0
000
00
0
Table 290. Debug Comparator Control Register DBGBCTL (Comparator B)
Address: 0x0028
7
6
5
432
10
R
SZE
SZ
TAG
BRK
RW
RWE
0
COMPE
W
Reset
0
000
00
0
Table 291. Debug Comparator Control Register DBGCCTL (Comparator C)
Address: 0x0028
7
6
5
432
10
R0
0
TAG
BRK
RW
RWE
0
COMPE
W
Reset
0
000
00
0
Table 292. DBGXCTL Field Descriptions
Field
Description
7
SZE
(Comparator B)
Size Comparator Enable Bit — The SZE bit controls whether access size comparison is enabled for the associated
comparator. This bit is ignored if the TAG bit in the same register is set.
0 Word/Byte access size is not used in comparison
1 Word/Byte access size is used in comparison
6
NDB
(Comparator A)
Not Data Bus — The NDB bit controls whether the match occurs when the data bus matches the comparator register value
or when the data bus differs from the register value. This bit is ignored if the TAG bit in the same register is set. This bit is
only available for comparator A.
0 Match on data bus equivalence to comparator register contents
1 Match on data bus difference to comparator register contents
6
SZ
(Comparator B)
Size Comparator Value Bit — The SZ bit selects either word or byte access size in comparison for the associated
comparator. This bit is ignored if the SZE bit is cleared or if the TAG bit in the same register is set. This bit is only featured
in comparator B.
0 Word access size will be compared
1 Byte access size will be compared