Chapter 5 Background Debug Controller (S12ZBDCV2)
S12ZVHY/S12ZVHL Family Reference Manual Rev. 1.05
Freescale Semiconductor
169
Table 5-10. Field Location to Byte Access Mapping
5.4.5.2.1
FILL_MEM and DUMP_MEM Increments and Alignment
FILL_MEM and DUMP_MEM increment the previously accessed address by the previous access size to
calculate the address of the current access. On misaligned longword accesses, the address bits [1:0] are
forced to zero, therefore the following FILL_MEM or DUMP_MEM increment to the first address in the
next 4-byte field. This is shown in
, the address of the first DUMP_MEM.32 following
READ_MEM.32 being calculated from 04.
When misaligned word accesses are realigned, then the original address (not the realigned address) is
incremented for the following FILL_MEM, DUMP_MEM command.
Misaligned word accesses can cause the same locations to be read twice as shown in rows 6 and 7. The
hardware ensures alignment at an attempted misaligned word access across a 4-byte boundary, as shown
in row 7. The following word access in row 8 continues from the realigned address of row 7.
d
Address[1:0]
Access Size
00
01
10
11
Note
00
32-bit Data[31:24]
Data[23:16]
Data
[15:8]
Data
[7:0]
01
32-bit Data[31:24]
Data[23:16]
Data
[15:8]
Data
[7:0]
Realigned
10
32-bit Data[31:24]
Data[23:16]
Data
[15:8]
Data
[7:0]
Realigned
11
32-bit Data[31:24]
Data[23:16]
Data
[15:8]
Data
[7:0]
Realigned
00
16-bit
Data [15:8]
Data [7:0]
01
16-bit
Data [15:8]
Data [7:0]
10
16-bit
Data [15:8]
Data [7:0]
11
16-bit
Data [15:8]
Data [7:0]
Realigned
00
8-bit Data
[7:0]
01
8-bit
Data [7:0]
10
8-bit
Data [7:0]
11
8-bit
Data [7:0]
Denotes byte that is not transmitted
Table 5-11. Consecutive Accesses With Variable Size
Row
Command
Address
Address[1:0]
00
01
10
11
1
READ_MEM.32
0x004003
11
Accessed
Accessed
Accessed
Accessed
2
DUMP_MEM.32
0x004004
00
Accessed
Accessed
Accessed
Accessed
3
DUMP_MEM.16
0x004008
00
Accessed
Accessed
4
DUMP_MEM.16
0x00400A
10
Accessed
Accessed
5
DUMP_MEM.08
0x00400C
00
Accessed
6
DUMP_MEM.16
0x00400D
01
Accessed
Accessed
7
DUMP_MEM.16
0x00400E
10
Accessed
Accessed
8
DUMP_MEM.16
0x004010
01
Accessed
Accessed
