MC9S12GRMV1 Datasheet, PDF (333/1292 Pages) Freescale Semiconductor, Inc – MC9S12G Family Reference Manual and Data Sheet

S12S Debug Module (S12SDBGV2)
Table 8-32. Comparator C Access Considerations
Condition For Valid Match
Read and write accesses of ADDR[n]
Comp C Address RWE RW
ADDR[n]¹
0
X
Write accesses of ADDR[n]
ADDR[n]
1
0
Read accesses of ADDR[n]
ADDR[n]
1
1
1 _{A word access of ADDR[n-1] also accesses ADDR[n] but does not generate a match.}
The comparator address register must contain the exact address from the code.
Examples
LDAA ADDR[n]
STAA #$BYTE ADDR[n]
STAA #$BYTE ADDR[n]
LDAA #$BYTE ADDR[n]
8.4.2.1.2 Comparator B
Comparator B offers address, direction (R/W) and access size (word/byte) comparison. If the SZE bit is
set the access size (word or byte) is compared with the SZ bit value such that only the specified size of
access causes a match. Thus if configured for a byte access of a particular address, a word access covering
the same address does not lead to match.
Assuming the access direction is not qualified (RWE=0), for simplicity, the size access considerations are
shown in Table 8-33.
Table 8-33. Comparator B Access Size Considerations
Condition For Valid Match
Word and byte accesses of ADDR[n]
Comp B Address RWE SZE SZ8
ADDR[n]¹
0
0
X
Word accesses of ADDR[n] only
ADDR[n]
0
1
0
Byte accesses of ADDR[n] only
ADDR[n]
0
1
1
1 _{A word access of ADDR[n-1] also accesses ADDR[n] but does not generate a match.}
The comparator address register must contain the exact address from the code.
Examples
MOVB #$BYTE ADDR[n]
MOVW #$WORD ADDR[n]
MOVW #$WORD ADDR[n]
LDD ADDR[n]
MOVB #$BYTE ADDR[n]
LDAB ADDR[n]
Access direction can also be used to qualify a match for Comparator B in the same way as described for
Comparator C in Table 8-32.
8.4.2.1.3 Comparator A
Comparator A offers address, direction (R/W), access size (word/byte) and data bus comparison.
Table 8-34 lists access considerations with data bus comparison. On word accesses the data byte of the
lower address is mapped to DBGADH. Access direction can also be used to qualify a match for
Comparator A in the same way as described for Comparator C in Table 8-32.
Table 8-34. Comparator A Matches When Accessing ADDR[n]
SZE
SZ
DBGADHM,
DBGADLM
0
X
$0000
Byte
Word
Access
DH=DBGADH, DL=DBGADL
Comment
No databus comparison
MC9S12G Family Reference Manual, Rev.1.23
Freescale Semiconductor
335