Used for save/restore of DBGDTRTXint. It is a component of the Debug Communication Channel.
AArch32 System register DBGDTRTXext bits [31:0] are architecturally mapped to AArch64 System register OSDTRTX_EL1[31:0].
This register is present only when EL1 is capable of using AArch32. Otherwise, direct accesses to DBGDTRTXext are UNDEFINED.
DBGDTRTXext is a 32-bit register.
| 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 |
| DTRTX | |||||||||||||||||||||||||||||||
Return DTRTX without side-effect.
Reads of this register return the value in DTRTX and do not change TXfull.
Writes of this register update the value in DTRTX and do not change TXfull.
For the full behavior of the Debug Communications Channel, see 'The Debug Communication Channel and Instruction Transfer Register'.
The reset behavior of this field is:
Arm deprecates reads and writes of DBGDTRTXext through the System register interface when the OS Lock is unlocked, DBGOSLSR.OSLK == 0.
Accesses to this register use the following encodings in the System register encoding space:
MRC{<c>}{<q>} <coproc>, {#}<opc1>, <Rt>, <CRn>, <CRm>{, {#}<opc2>}
| coproc | opc1 | CRn | CRm | opc2 |
|---|---|---|---|---|
| 0b1110 | 0b000 | 0b0000 | 0b0011 | 0b010 |
if PSTATE.EL == EL0 then UNDEFINED; elsif Halted() && ConstrainUnpredictableBool(Unpredictable_IGNORETRAPINDEBUG) then R[t] = DBGDTRTXext; elsif PSTATE.EL == EL1 then if HaveEL(EL3) && EL3SDDUndefPriority() && !ELUsingAArch32(EL3) && MDCR_EL3.TDCC == '1' then UNDEFINED; elsif HaveEL(EL3) && EL3SDDUndefPriority() && ELUsingAArch32(EL3) && SDCR.TDCC == '1' then UNDEFINED; elsif HaveEL(EL3) && EL3SDDUndefPriority() && !ELUsingAArch32(EL3) && MDCR_EL3.TDA == '1' then UNDEFINED; elsif EL2Enabled() && !ELUsingAArch32(EL2) && MDCR_EL2.TDCC == '1' then AArch64.AArch32SystemAccessTrap(EL2, 0x05); elsif EL2Enabled() && ELUsingAArch32(EL2) && HDCR.TDCC == '1' then AArch32.TakeHypTrapException(0x05); 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.TDCC == '1' then if EL3SDDUndef() then UNDEFINED; else AArch64.AArch32SystemAccessTrap(EL3, 0x05); elsif HaveEL(EL3) && ELUsingAArch32(EL3) && SDCR.TDCC == '1' then if EL3SDDUndef() then UNDEFINED; else AArch32.TakeMonitorTrapException(); elsif HaveEL(EL3) && !ELUsingAArch32(EL3) && MDCR_EL3.TDA == '1' then if EL3SDDUndef() then UNDEFINED; else AArch64.AArch32SystemAccessTrap(EL3, 0x05); else R[t] = DBGDTRTXext; elsif PSTATE.EL == EL2 then if HaveEL(EL3) && EL3SDDUndefPriority() && !ELUsingAArch32(EL3) && MDCR_EL3.TDCC == '1' then UNDEFINED; elsif HaveEL(EL3) && EL3SDDUndefPriority() && ELUsingAArch32(EL3) && SDCR.TDCC == '1' then UNDEFINED; elsif HaveEL(EL3) && EL3SDDUndefPriority() && !ELUsingAArch32(EL3) && MDCR_EL3.TDA == '1' then UNDEFINED; elsif HaveEL(EL3) && !ELUsingAArch32(EL3) && MDCR_EL3.TDCC == '1' then if EL3SDDUndef() then UNDEFINED; else AArch64.AArch32SystemAccessTrap(EL3, 0x05); elsif HaveEL(EL3) && ELUsingAArch32(EL3) && SDCR.TDCC == '1' then if EL3SDDUndef() then UNDEFINED; else AArch32.TakeMonitorTrapException(); elsif HaveEL(EL3) && !ELUsingAArch32(EL3) && MDCR_EL3.TDA == '1' then if EL3SDDUndef() then UNDEFINED; else AArch64.AArch32SystemAccessTrap(EL3, 0x05); else R[t] = DBGDTRTXext; elsif PSTATE.EL == EL3 then if PSTATE.M != M32_Monitor && SDCR.TDCC == '1' then AArch32.TakeMonitorTrapException(); else R[t] = DBGDTRTXext;
MCR{<c>}{<q>} <coproc>, {#}<opc1>, <Rt>, <CRn>, <CRm>{, {#}<opc2>}
| coproc | opc1 | CRn | CRm | opc2 |
|---|---|---|---|---|
| 0b1110 | 0b000 | 0b0000 | 0b0011 | 0b010 |
if PSTATE.EL == EL0 then UNDEFINED; elsif Halted() && ConstrainUnpredictableBool(Unpredictable_IGNORETRAPINDEBUG) then DBGDTRTXext = R[t]; elsif PSTATE.EL == EL1 then if HaveEL(EL3) && EL3SDDUndefPriority() && !ELUsingAArch32(EL3) && MDCR_EL3.TDCC == '1' then UNDEFINED; elsif HaveEL(EL3) && EL3SDDUndefPriority() && ELUsingAArch32(EL3) && SDCR.TDCC == '1' then UNDEFINED; elsif HaveEL(EL3) && EL3SDDUndefPriority() && !ELUsingAArch32(EL3) && MDCR_EL3.TDA == '1' then UNDEFINED; elsif EL2Enabled() && !ELUsingAArch32(EL2) && MDCR_EL2.TDCC == '1' then AArch64.AArch32SystemAccessTrap(EL2, 0x05); elsif EL2Enabled() && ELUsingAArch32(EL2) && HDCR.TDCC == '1' then AArch32.TakeHypTrapException(0x05); 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.TDCC == '1' then if EL3SDDUndef() then UNDEFINED; else AArch64.AArch32SystemAccessTrap(EL3, 0x05); elsif HaveEL(EL3) && ELUsingAArch32(EL3) && SDCR.TDCC == '1' then if EL3SDDUndef() then UNDEFINED; else AArch32.TakeMonitorTrapException(); elsif HaveEL(EL3) && !ELUsingAArch32(EL3) && MDCR_EL3.TDA == '1' then if EL3SDDUndef() then UNDEFINED; else AArch64.AArch32SystemAccessTrap(EL3, 0x05); else DBGDTRTXext = R[t]; elsif PSTATE.EL == EL2 then if HaveEL(EL3) && EL3SDDUndefPriority() && !ELUsingAArch32(EL3) && MDCR_EL3.TDCC == '1' then UNDEFINED; elsif HaveEL(EL3) && EL3SDDUndefPriority() && ELUsingAArch32(EL3) && SDCR.TDCC == '1' then UNDEFINED; elsif HaveEL(EL3) && EL3SDDUndefPriority() && !ELUsingAArch32(EL3) && MDCR_EL3.TDA == '1' then UNDEFINED; elsif HaveEL(EL3) && !ELUsingAArch32(EL3) && MDCR_EL3.TDCC == '1' then if EL3SDDUndef() then UNDEFINED; else AArch64.AArch32SystemAccessTrap(EL3, 0x05); elsif HaveEL(EL3) && ELUsingAArch32(EL3) && SDCR.TDCC == '1' then if EL3SDDUndef() then UNDEFINED; else AArch32.TakeMonitorTrapException(); elsif HaveEL(EL3) && !ELUsingAArch32(EL3) && MDCR_EL3.TDA == '1' then if EL3SDDUndef() then UNDEFINED; else AArch64.AArch32SystemAccessTrap(EL3, 0x05); else DBGDTRTXext = R[t]; elsif PSTATE.EL == EL3 then if PSTATE.M != M32_Monitor && SDCR.TDCC == '1' then AArch32.TakeMonitorTrapException(); else DBGDTRTXext = R[t];