Intel® IXP42X product line and IXC1100 control plane processors—Intel XScale® Processor
Intel® IXP42X Product Line of Network Processors and IXC1100 Control Plane Processor
DM September 2006
96 Order Number: 252480-006US
An instruction breakpoint will generate a debug exception before the instruction at the
address specified in the ICBR executes. When an instruction breakpoint occurs, the
processor sets the DBCR.moe bits to 0b001.
Software must disable the breakpoint before exiting the handler. This allows the break-
pointed instruction to execute after the exception is handled.
Single step execution is accomplished using the instruction breakpoint registers and
must be completely handled in software (either on the host or by the debug handler).
3.6.6.2 Data Breakpoints
IXP42X product line and IXC1100 control plane processors’ debug architecture defines
two data breakpoint registers (DBR0, DBR1). The format of the registers is shown in
Tabl e 36.
DBR0 is a dedicated data address breakpoint register. DBR1 can be programmed for
one of two operations:
Data address mask
Second data address breakpoint
The DBCON register controls the functionality of DBR1, as well as the enables for both
DBRs. DBCON also controls what type of memory access to break on.
Table 35. Instruction Breakpoint Address and Control Register (IBCRx)
31 30 29 28 27 26 25 24 23 22 21 20 19 18 17 16 15 14 13 12 11 10 9876543210
IBCRx E
reset value: unpredictable address, disabled
Bits Access Description
31:1 Read / Write Instruction Breakpoint MVA
in ARM mode, IBCRx[1] is ignored
0Read / Write IBCRx Enable (E) -
0 = Breakpoint disabled
1 = Breakpoint enabled
Table 36. Data Breakpoint Register (DBRx)
31 30 29 28 27 26 25 24 23 22 21 20 19 18 17 16 15 14 13 12 11 10 9876543210
DBRx
reset value: unpredictable
Bits Access Description
31:0 Read / Write
DBR0: Data Breakpoint MVA
DBR1:
Data Address Mask OR
Data Breakpoint MVA