The DBGBVR<n> characteristics are:
Holds a value for use in breakpoint matching, either the virtual address of an instruction or a context ID. Forms breakpoint n together with control register DBGBCR<n>. If EL2 is implemented and this breakpoint supports Context matching, DBGBVR<n> can be associated with a Breakpoint Extended Value Register DBGBXVR<n> for VMID matching.
This register is part of the Debug registers functional group.
There is one instance of this register that is used in both Secure and Non-secure states.
AArch32 System register DBGBVR<n> is architecturally mapped to AArch64 System register DBGBVR<n>_EL1[31:0] .
AArch32 System register DBGBVR<n> is architecturally mapped to External register DBGBVR<n>_EL1[31:0] .
If breakpoint n is not implemented then this register is unallocated.
This register is in the Cold reset domain. On a Cold reset RW fields in this register reset to architecturally UNKNOWN values. The register is not affected by a Warm reset.
How this register is interpreted depends on the value of DBGBCR<n>.BT.
For other values of DBGBCR<n>.BT, this register is RES0.
Some breakpoints might not support Context ID comparison. For more information, see the description of the DBGDIDR.CTX_CMPs field.
The DBGBVR<n> bit assignments are:
31 | 30 | 29 | 28 | 27 | 26 | 25 | 24 | 23 | 22 | 21 | 20 | 19 | 18 | 17 | 16 | 15 | 14 | 13 | 12 | 11 | 10 | 9 | 8 | 7 | 6 | 5 | 4 | 3 | 2 | 1 | 0 |
VA[31:2] | 0 | 0 |
Bits[31:2] of the address value for comparison.
When this register has an architecturally-defined reset value, this field resets to a value that is architecturally UNKNOWN.
Reserved, RES0.
31 | 30 | 29 | 28 | 27 | 26 | 25 | 24 | 23 | 22 | 21 | 20 | 19 | 18 | 17 | 16 | 15 | 14 | 13 | 12 | 11 | 10 | 9 | 8 | 7 | 6 | 5 | 4 | 3 | 2 | 1 | 0 |
ContextID |
Context ID value for comparison.
The value is compared against CONTEXTIDR in the following cases:
When ARMv8.1-VHE is implemented, EL2 is using AArch64, HCR_EL2.{E2H, TGE} is {1, 1} and the PE is in Non-secure EL0, the value is compared against CONTEXTIDR_EL2.
When this register has an architecturally-defined reset value, this field resets to a value that is architecturally UNKNOWN.
31 | 30 | 29 | 28 | 27 | 26 | 25 | 24 | 23 | 22 | 21 | 20 | 19 | 18 | 17 | 16 | 15 | 14 | 13 | 12 | 11 | 10 | 9 | 8 | 7 | 6 | 5 | 4 | 3 | 2 | 1 | 0 |
ContextID |
Context ID value for comparison against CONTEXTIDR.
When this register has an architecturally-defined reset value, this field resets to a value that is architecturally UNKNOWN.
31 | 30 | 29 | 28 | 27 | 26 | 25 | 24 | 23 | 22 | 21 | 20 | 19 | 18 | 17 | 16 | 15 | 14 | 13 | 12 | 11 | 10 | 9 | 8 | 7 | 6 | 5 | 4 | 3 | 2 | 1 | 0 |
ContextID |
Context ID value for comparison against CONTEXTIDR_EL2.
When this register has an architecturally-defined reset value, this field resets to a value that is architecturally UNKNOWN.
This register can be read using MRC with the following syntax:
MRC <syntax>
This register can be written using MCR with the following syntax:
MCR <syntax>
This syntax uses the following encoding in the System instruction encoding space:
<syntax> | opc1 | opc2 | CRn | coproc | CRm |
---|---|---|---|---|---|
p14, 0, <Rt>, c0, <CRm>, 4 | 000 | 100 | 0000 | 1110 | n<3:0> |
The register is accessible as follows:
Control | Accessibility | |||||
---|---|---|---|---|---|---|
E2H | TGE | NS | EL0 | EL1 | EL2 | EL3 |
x | x | 0 | - | RW | n/a | RW |
x | 0 | 1 | - | RW | RW | RW |
x | 1 | 1 | - | n/a | RW | RW |
This table applies to all instructions that can access this register.
For a description of the prioritization of any generated exceptions, see section G1.11.2 (Exception priority order) in the ARM® Architecture Reference Manual, ARMv8, for ARMv8-A architecture profile for exceptions taken to AArch32 state, and section D1.13.2 (Synchronous exception prioritization) for exceptions taken to AArch64 state. Subject to the prioritization rules, the following traps and enables are applicable when accessing this register.
In both Security states, and not dependent on other configuration bits:
If EDSCR.TDA==1, and DBGOSLSR.OSLK==0, accesses to this register from PL1 and PL2 are trapped to Debug state.
When EL2 is implemented and is using AArch64 and SCR_EL3.NS==1 :
If MDCR_EL2.TDA==1, Non-secure accesses to this register from EL1 are trapped to EL2.
When EL2 is implemented and is using AArch32 and SCR_EL3.NS==1 :
If HDCR.TDA==1, Non-secure accesses to this register from EL1 are trapped to Hyp mode.
When EL3 is implemented and is using AArch64 :
If MDCR_EL3.TDA==1, accesses to this register from EL1 and EL2 are trapped to EL3.
02/05/2017 15:43
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