MCF548x Reference Manual, Rev. 3
8-24 Freescale Semiconductor
DBRs support both aligned and misaligned references. Table 8-19 shows relationships between processor
address, access size, and location within the 32-bit data bus.

8.4.10 PC Breakpoint ASID Register (PBASID)

Each PC breakpoint register (PBR, PBR1, PBR2, or PBR3) specifies an instruction address that can be
used to trigger a breakpoint. To support debugging in a virtual environment, an ASID can optionally be
associated with the instruction address in the PC breakpoint registers. The optional specification of an
ASID value is made using PBASID and its exact inclusion within the breakpoint specification defined by
the PBAC.
PBASID contains one 8-bit ASID values for each PC breakpoint register, as described in Table 8-20,
which allows each PC breakpoint register to be associated with a unique virtual address and process.
Table 8-19. Access Size and Operand Data Location
A[1:0] Access Size Operand Location
00 Byte D[31:24]
01 Byte D[23:16]
10 Byte D[15:8]
11 Byte D[7:0]
0x Word D[31:16]
1x Word D[15:0]
xx Longword D[31:0]
31 30 29 28 27 26 25 24 23 22 21 20 19 18 17 16
R PBR3ASID PBR2ASID
W
Reset0000000000000000
1514131211109876543210
R PBR1ASID PBRASID
W
Reset0000000000000000
Reg
Addr
CPU + 0x14
Figure 8-16. PC Breakpoint ASID Register (PBASID)
Table 8-20. PBASID Field Descriptions
Bits Name Description
31–24 PBA3SID PBR3ASID. Corresponds to the ASID associated with PBR3.
23–16 PBA2SID PBR2ASID Corresponds to the ASID associated with PBR2.