ARM Architecture Reference Manual ARMv7-A and ARMv7-R edition

Condition for breakpoint generation on IVA match, without address range masking
Debug Events
When BRPn is programmed for IVA match, without address range masking, and all other conditions for
generating a breakpoint are met, a Breakpoint debug event is generated only if both:
bits [31:2] of the IVA are equal to the value of bits [31:2] of DBGBVRn
the Byte address select field, bits [8:5], of DBGBCRn is programmed for an IVA match for the
current Instruction set state and IVA[1:0] value, see Byte address selection behavior on IVA match or
mismatch on page C10-55.
Note
In v7 Debug, to perform IVA comparison without address range masking you must set DBGBCR[28:24],
the Address range mask field, to zero.
Condition for breakpoint generation on IVA mismatch, without address range masking
When BRPn is programmed for IVA mismatch, without address range masking, and all other conditions for
generating a breakpoint are met, a Breakpoint debug event is generated only if either:
bits [31:2] of the IVA are not equal to the value of bits [31:2] of DBGBVRn
the Byte address select field, bits [8:5], of DBGBCRn is programmed for an IVA mismatch for the
current Instruction set state and IVA[1:0] value, see Byte address selection behavior on IVA match or
mismatch on page C10-55.
Note
In v7 Debug, to perform IVA comparison without address range masking you must set DBGBCR[28:24],
the Address range mask field, to zero.
Breakpoint address range masking behavior, v7 Debug
When BRPn is programmed for IVA matching, the comparison is masked using the value held in the
Address range mask field, DBGBCRn[28:24].
You can use the Address range mask field when programming the BRP for IVA mismatch, that is, when
DBGBCR[28:24] != 0b00000 and DBGBCR[22] == 1. In this case, the address comparison portion of
breakpoint generation hits for all addresses outside the masked address region.
If an implementation does not support breakpoint address range masking, the Address range mask field is
RAZ.
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