AMCC PPC405 - 8.8.2 Debug Status Register (DBSR)

AMCC Proprietary 145
Revision 1.02 - September 10, 2007
PPC405 Processor
Preliminary User’s Manual
8.8.2 Debug Status Register (DBSR)
The DBSR contains status on debug events and the most recent reset; the status is obtained by reading the DBSR.
The status bits are normally set by debug events or by any of the three reset types.
Clearing DBSR fields is performed by writing a word to the DBSR, using the
mtdbsr extended mnemonic, having
a 1 in all bit positions to be cleared and a 0 in the all other bit positions. The data written to the DBSR is not direct
data, but a mask. A 1 clears the bit and a 0 has no effect.
Application code must not use the DBSR.
12:13 DV1M
Data Value Compare 1 Mode:
00 Undefined
01 AND
10 OR
11 AND-OR
Type of data comparison used:
All bytes selected by DBCR1[DV1BE] must com-
pare to the appropriate bytes of DVC1.
One of the bytes selected by DBCR1[DV1BE] must
compare to the appropriate bytes of DVC1.
The upper halfword or lower halfword must com-
pare to the appropriate halfword in DVC1. When
performing halfword compares set DBCR1[DV1BE]
= 0011, 1100, or 1111.
14:15 DV2M
Data Value Compare 2 Mode:
00 Undefined
01 AND
10 OR
11 AND-OR
Type of data comparison used
All bytes selected by DBCR1[DV2BE] must com-
pare to the appropriate bytes of DVC2.
One of the bytes selected by DBCR1[DV2BE] must
compare to the appropriate bytes of DVC2.
The upper halfword or lower halfword must com-
pare to the appropriate halfword in DVC2. When
performing halfword compares set DBCR1[DV2BE]
= 0011, 1100, or 1111.
16:19 DV1BE
Data Value Compare 1 Byte:
0 Disabled
1 Enabled
Selects which data bytes to use in data value com-
parison
20:23 DV2BE
Data Value Compare 2 Byte:
0 Disabled
1 Enabled
Selects which data bytes to use in data value com-
parison
24:31
Reserved
Figure 8-3. Debug Status Register (DBSR)
0IC
Instruction Completion Debug Event:
0 Event did not occur
1 Event occurred
1BT
Branch Taken Debug Event:
0 Event did not occur
1 Event occurred
2EDE
Exception Debug Event:
0 Event did not occur
1 Event occurred