Controls behavior of the PE on powerdown request.
AArch32 System register DBGPRCR bits [31:0] are architecturally mapped to AArch64 System register DBGPRCR_EL1[31:0].
This register is present only when EL1 is capable of using AArch32. Otherwise, direct accesses to DBGPRCR are UNDEFINED.
Bit [0] of this register is mapped to EDPRCR.CORENPDRQ, bit [0] of the external view of this register.
The other bits in these registers are not mapped to each other.
DBGPRCR 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 |
| RES0 | CORENPDRQ | ||||||||||||||||||||||||||||||
Reserved, RES0.
Core no powerdown request. Requests emulation of powerdown.
This request is typically passed to an external power controller. This means that whether a request causes power up is dependent on the IMPLEMENTATION DEFINED nature of the system. The power controller must not allow the Core power domain to switch off while this bit is 1.
| CORENPDRQ | Meaning |
|---|---|
| 0b0 |
If the system responds to a powerdown request, it powers down Core power domain. |
| 0b1 |
If the system responds to a powerdown request, it does not powerdown the Core power domain, but instead emulates a powerdown of that domain. |
In an implementation that includes the recommended external debug interface, this bit drives the DBGNOPWRDWN signal.
It is IMPLEMENTATION DEFINED whether this bit is reset to the Cold reset value on exit from an IMPLEMENTATION DEFINED software-visible retention state. For more information about retention states see 'Core power domain power states'.
Writes to this bit are not prohibited by the IMPLEMENTATION DEFINED authentication interface. This means that a debugger can request emulation of powerdown regardless of whether invasive debug is permitted.
On a Cold reset, if the powerup request is implemented and the powerup request has been asserted, this field is set to an IMPLEMENTATION DEFINED choice of 0 or 1. If the powerup request is not asserted, this field is set to 0.
Core no powerdown request. Requests emulation of powerdown.
This request is typically passed to an external power controller. This means that whether a request causes power up is dependent on the IMPLEMENTATION DEFINED nature of the system. The power controller must not allow the Core power domain to switch off while this bit is 1.
| CORENPDRQ | Meaning |
|---|---|
| 0b0 |
If the system responds to a powerdown request, it powers down Core power domain. |
| 0b1 |
If the system responds to a powerdown request, it does not powerdown the Core power domain, but instead emulates a powerdown of that domain. |
In an implementation that includes the recommended external debug interface, this bit drives the DBGNOPWRDWN signal.
It is IMPLEMENTATION DEFINED whether this bit is reset to the value of EDPRCR.COREPURQ on exit from an IMPLEMENTATION DEFINED software-visible retention state. For more information about retention states see 'Core power domain power states'.
Writes to this bit are not prohibited by the IMPLEMENTATION DEFINED authentication interface. This means that a debugger can request emulation of powerdown regardless of whether invasive debug is permitted.
The reset behavior of this field is:
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 | 0b0001 | 0b0100 | 0b100 |
if PSTATE.EL == EL0 then UNDEFINED; elsif PSTATE.EL == EL1 then if HaveEL(EL3) && EL3SDDUndefPriority() && !ELUsingAArch32(EL3) && MDCR_EL3.TDOSA == '1' then UNDEFINED; elsif EL2Enabled() && !ELUsingAArch32(EL2) && MDCR_EL2.<TDE,TDOSA> != '00' then AArch64.AArch32SystemAccessTrap(EL2, 0x05); elsif EL2Enabled() && ELUsingAArch32(EL2) && HDCR.<TDE,TDOSA> != '00' then AArch32.TakeHypTrapException(0x05); elsif HaveEL(EL3) && !ELUsingAArch32(EL3) && MDCR_EL3.TDOSA == '1' then if EL3SDDUndef() then UNDEFINED; else AArch64.AArch32SystemAccessTrap(EL3, 0x05); else R[t] = DBGPRCR; elsif PSTATE.EL == EL2 then if HaveEL(EL3) && EL3SDDUndefPriority() && !ELUsingAArch32(EL3) && MDCR_EL3.TDOSA == '1' then UNDEFINED; elsif HaveEL(EL3) && !ELUsingAArch32(EL3) && MDCR_EL3.TDOSA == '1' then if EL3SDDUndef() then UNDEFINED; else AArch64.AArch32SystemAccessTrap(EL3, 0x05); else R[t] = DBGPRCR; elsif PSTATE.EL == EL3 then R[t] = DBGPRCR;
MCR{<c>}{<q>} <coproc>, {#}<opc1>, <Rt>, <CRn>, <CRm>{, {#}<opc2>}
| coproc | opc1 | CRn | CRm | opc2 |
|---|---|---|---|---|
| 0b1110 | 0b000 | 0b0001 | 0b0100 | 0b100 |
if PSTATE.EL == EL0 then UNDEFINED; elsif PSTATE.EL == EL1 then if HaveEL(EL3) && EL3SDDUndefPriority() && !ELUsingAArch32(EL3) && MDCR_EL3.TDOSA == '1' then UNDEFINED; elsif EL2Enabled() && !ELUsingAArch32(EL2) && MDCR_EL2.<TDE,TDOSA> != '00' then AArch64.AArch32SystemAccessTrap(EL2, 0x05); elsif EL2Enabled() && ELUsingAArch32(EL2) && HDCR.<TDE,TDOSA> != '00' then AArch32.TakeHypTrapException(0x05); elsif HaveEL(EL3) && !ELUsingAArch32(EL3) && MDCR_EL3.TDOSA == '1' then if EL3SDDUndef() then UNDEFINED; else AArch64.AArch32SystemAccessTrap(EL3, 0x05); else DBGPRCR = R[t]; elsif PSTATE.EL == EL2 then if HaveEL(EL3) && EL3SDDUndefPriority() && !ELUsingAArch32(EL3) && MDCR_EL3.TDOSA == '1' then UNDEFINED; elsif HaveEL(EL3) && !ELUsingAArch32(EL3) && MDCR_EL3.TDOSA == '1' then if EL3SDDUndef() then UNDEFINED; else AArch64.AArch32SystemAccessTrap(EL3, 0x05); else DBGPRCR = R[t]; elsif PSTATE.EL == EL3 then DBGPRCR = R[t];