DBGDEVID1, Debug Device ID register 1

The DBGDEVID1 characteristics are:

Purpose

Adds to the information given by the DBGDIDR by describing other features of the debug implementation.

Configuration

This register is present only when AArch32 is supported at any Exception level. Otherwise, direct accesses to DBGDEVID1 are UNDEFINED.

This register is required in all implementations.

Attributes

DBGDEVID1 is a 32-bit register.

Field descriptions

The DBGDEVID1 bit assignments are:

313029282726252423222120191817161514131211109876543210
RES0PCSROffset

Bits [31:4]

Reserved, RES0.

PCSROffset, bits [3:0]

This field indicates the offset applied to PC samples returned by reads of EDPCSR. Permitted values of this field in Armv8 are:

PCSROffsetMeaning
0b0000

EDPCSR is not implemented.

0b0010

EDPCSR implemented. Samples have no offset applied and do not sample the instruction set state in AArch32 state.

When FEAT_PCSRv8p2 is implemented, the only permitted value is 0b0000.

Note

FEAT_PCSRv8p2 implements the PC Sample-based Profiling Extension in the Performance Monitors register space, as indicated by the value of PMDEVID.PCSample.

Accessing the DBGDEVID1

Accesses to this register use the following encodings:

MRC{<c>}{<q>} <coproc>, {#}<opc1>, <Rt>, <CRn>, <CRm>{, {#}<opc2>}

coprocopc1CRnCRmopc2
0b11100b0000b01110b00010b111

if 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'" && !ELUsingAArch32(EL3) && MDCR_EL3.TDA == '1' then UNDEFINED; elsif EL2Enabled() && !ELUsingAArch32(EL2) && MDCR_EL2.<TDE,TDA> != '00' then AArch64.AArch32SystemAccessTrap(EL2, 0x05); elsif EL2Enabled() && ELUsingAArch32(EL2) && HDCR.<TDE,TDA> != '00' then AArch32.TakeHypTrapException(0x05); elsif HaveEL(EL3) && !ELUsingAArch32(EL3) && MDCR_EL3.TDA == '1' then if Halted() && EDSCR.SDD == '1' then UNDEFINED; else AArch64.AArch32SystemAccessTrap(EL3, 0x05); else return DBGDEVID1; elsif PSTATE.EL == EL2 then if Halted() && HaveEL(EL3) && EDSCR.SDD == '1' && boolean IMPLEMENTATION_DEFINED "EL3 trap priority when SDD == '1'" && !ELUsingAArch32(EL3) && MDCR_EL3.TDA == '1' then UNDEFINED; elsif HaveEL(EL3) && !ELUsingAArch32(EL3) && MDCR_EL3.TDA == '1' then if Halted() && EDSCR.SDD == '1' then UNDEFINED; else AArch64.AArch32SystemAccessTrap(EL3, 0x05); else return DBGDEVID1; elsif PSTATE.EL == EL3 then return DBGDEVID1;


30/03/2021 20:51; e3551d56dc294a4d55296a6c10544191ada08a8e

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