DBGWVR<n>_EL1, Debug Watchpoint Value Registers, n = 0 - 15

The DBGWVR<n>_EL1 characteristics are:

Purpose

Holds a data address value for use in watchpoint matching. Forms watchpoint n together with control register DBGWCR<n>_EL1.

Configuration

AArch64 System register DBGWVR<n>_EL1 bits [31:0] are architecturally mapped to AArch32 System register DBGWVR<n>[31:0].

AArch64 System register DBGWVR<n>_EL1 bits [63:0] are architecturally mapped to External register DBGWVR<n>_EL1[63:0].

If watchpoint n is not implemented then accesses to this register are UNDEFINED.

Attributes

DBGWVR<n>_EL1 is a 64-bit register.

Field descriptions

6362616059585756555453525150494847464544434241403938373635343332
313029282726252423222120191817161514131211109876543210
RESS[14:8]Bits[56:53]Bits[52:49]VA[48:2]
VA[48:2]RES0

RESS[14:8], bits [63:57]

Reserved, Sign extended. Software must set all bits in this field to the same value as the most significant bit of the VA field. If all bits in this field are not the same value as the most significant bit of the VA field, then all of the following apply:

Bits[56:53]
When FEAT_LVA3 is implemented:

VA[56:53], bits [3:0] of bits [56:53]

Extension to VA[48:2]. For more information, see VA[48:2].

The reset behavior of this field is:


Otherwise:

RESS[7:4], bits [3:0] of bits [56:53]

Extension to RESS[14:8]. For more information, see RESS[14:8].

Bits[52:49]
When FEAT_LVA is implemented:

VA[52:49], bits [3:0] of bits [52:49]

Extension to VA[48:2]. For more information, see VA[48:2].

The reset behavior of this field is:


Otherwise:

RESS[3:0], bits [3:0] of bits [52:49]

Extension to RESS[14:8]. For more information, see RESS[14:8].

VA[48:2], bits [48:2]

Bits[48:2] of the address value for comparison.

When FEAT_LVA3 is implemented, (VA[56:53]:VA[52:49]) forms the upper part of the address value. Otherwise, bits [56:53] are part of the RESS field.

When FEAT_LVA is implemented, VA[52:49] forms the upper part of the address value. Otherwise, bits [52:49] are part of the RESS field.

Arm deprecates setting DBGWVR<n>_EL1[2] == 1.

The reset behavior of this field is:

Bits [1:0]

Reserved, RES0.

Accessing DBGWVR<n>_EL1

When FEAT_Debugv8p9 is implemented, a PE is permitted to support up to 64 implemented watchpoints.

Accesses to this register use the following encodings in the System register encoding space:

MRS <Xt>, DBGWVR<m>_EL1 ; Where m = 0-15

op0op1CRnCRmop2
0b100b0000b0000m[3:0]0b110

integer m = UInt(CRm<3:0>); if m >= NUM_WATCHPOINTS then UNDEFINED; elsif PSTATE.EL == EL0 then UNDEFINED; elsif PSTATE.EL == EL1 then if Halted() && HaveEL(EL3) && EDSCR.SDD == '1' && boolean IMPLEMENTATION_DEFINED "EL3 trap priority when SDD == '1'" && MDCR_EL3.TDA == '1' then UNDEFINED; elsif EL2Enabled() && IsFeatureImplemented(FEAT_FGT) && (!HaveEL(EL3) || SCR_EL3.FGTEn == '1') && HDFGRTR_EL2.DBGWVRn_EL1 == '1' then AArch64.SystemAccessTrap(EL2, 0x18); elsif EL2Enabled() && MDCR_EL2.<TDE,TDA> != '00' then AArch64.SystemAccessTrap(EL2, 0x18); elsif HaveEL(EL3) && MDCR_EL3.TDA == '1' then if Halted() && EDSCR.SDD == '1' then UNDEFINED; else AArch64.SystemAccessTrap(EL3, 0x18); elsif OSLSR_EL1.OSLK == '0' && HaltingAllowed() && EDSCR.TDA == '1' then Halt(DebugHalt_SoftwareAccess); else X[t, 64] = DBGWVR_EL1[m]; elsif PSTATE.EL == EL2 then if Halted() && HaveEL(EL3) && EDSCR.SDD == '1' && boolean IMPLEMENTATION_DEFINED "EL3 trap priority when SDD == '1'" && MDCR_EL3.TDA == '1' then UNDEFINED; elsif HaveEL(EL3) && MDCR_EL3.TDA == '1' then if Halted() && EDSCR.SDD == '1' then UNDEFINED; else AArch64.SystemAccessTrap(EL3, 0x18); elsif OSLSR_EL1.OSLK == '0' && HaltingAllowed() && EDSCR.TDA == '1' then Halt(DebugHalt_SoftwareAccess); else X[t, 64] = DBGWVR_EL1[m]; elsif PSTATE.EL == EL3 then if OSLSR_EL1.OSLK == '0' && HaltingAllowed() && EDSCR.TDA == '1' then Halt(DebugHalt_SoftwareAccess); else X[t, 64] = DBGWVR_EL1[m];

MSR DBGWVR<m>_EL1, <Xt> ; Where m = 0-15

op0op1CRnCRmop2
0b100b0000b0000m[3:0]0b110

integer m = UInt(CRm<3:0>); if m >= NUM_WATCHPOINTS then UNDEFINED; elsif PSTATE.EL == EL0 then UNDEFINED; elsif PSTATE.EL == EL1 then if Halted() && HaveEL(EL3) && EDSCR.SDD == '1' && boolean IMPLEMENTATION_DEFINED "EL3 trap priority when SDD == '1'" && MDCR_EL3.TDA == '1' then UNDEFINED; elsif EL2Enabled() && IsFeatureImplemented(FEAT_FGT) && (!HaveEL(EL3) || SCR_EL3.FGTEn == '1') && HDFGWTR_EL2.DBGWVRn_EL1 == '1' then AArch64.SystemAccessTrap(EL2, 0x18); elsif EL2Enabled() && MDCR_EL2.<TDE,TDA> != '00' then AArch64.SystemAccessTrap(EL2, 0x18); elsif HaveEL(EL3) && MDCR_EL3.TDA == '1' then if Halted() && EDSCR.SDD == '1' then UNDEFINED; else AArch64.SystemAccessTrap(EL3, 0x18); elsif OSLSR_EL1.OSLK == '0' && HaltingAllowed() && EDSCR.TDA == '1' then Halt(DebugHalt_SoftwareAccess); else DBGWVR_EL1[m] = X[t, 64]; elsif PSTATE.EL == EL2 then if Halted() && HaveEL(EL3) && EDSCR.SDD == '1' && boolean IMPLEMENTATION_DEFINED "EL3 trap priority when SDD == '1'" && MDCR_EL3.TDA == '1' then UNDEFINED; elsif HaveEL(EL3) && MDCR_EL3.TDA == '1' then if Halted() && EDSCR.SDD == '1' then UNDEFINED; else AArch64.SystemAccessTrap(EL3, 0x18); elsif OSLSR_EL1.OSLK == '0' && HaltingAllowed() && EDSCR.TDA == '1' then Halt(DebugHalt_SoftwareAccess); else DBGWVR_EL1[m] = X[t, 64]; elsif PSTATE.EL == EL3 then if OSLSR_EL1.OSLK == '0' && HaltingAllowed() && EDSCR.TDA == '1' then Halt(DebugHalt_SoftwareAccess); else DBGWVR_EL1[m] = X[t, 64];


30/09/2022 15:58; 21c5a6dd0fdaf10a712e2f2d6fffbdbd66d4d96f

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