DBGPRCR_EL1, Debug Power Control Register

The DBGPRCR_EL1 characteristics are:

Purpose

Controls behavior of the PE on powerdown request.

This register is part of the Debug registers functional group.

Configuration

AArch64 System register DBGPRCR_EL1 is architecturally mapped to AArch32 System register DBGPRCR.

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.

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.

Attributes

DBGPRCR_EL1 is a 32-bit register.

Field descriptions

The DBGPRCR_EL1 bit assignments are:

313029282726252423222120191817161514131211109876543210
0000000000000000000000000000000CORENPDRQ

Bits [31:1]

Reserved, RES0.

CORENPDRQ, bit [0]

Core no powerdown request. Requests emulation of powerdown. Possible values of this bit are:

CORENPDRQMeaning
0

If the system responds to a powerdown request, it powers down Core power domain.

1

If the system responds to a powerdown request, it does not powerdown the Core power domain, but instead emulates a powerdown of that domain.

Writes to this bit are permitted regardless of the state of the IMPLEMENTATION DEFINED authentication interface. This means that a debugger can request Core no powerdown regardless of whether invasive debug is permitted.

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.

Accessing the DBGPRCR_EL1

This register can be read using MRS with the following syntax:

MRS <Xt>, <systemreg>

This register can be written using MSR (register) with the following syntax:

MSR <systemreg>, <Xt>

This syntax uses the following encoding in the System instruction encoding space:

<systemreg> op0op1CRnCRmop2
DBGPRCR_EL11000000010100100

Accessibility

The register is accessible as follows:

Control Accessibility
E2HTGENSEL0EL1EL2EL3
xx0 - RW n/a RW
x01 - RWRWRW
x11 - n/a RWRW

This table applies to all instructions that can access this register.

Traps and enables

For a description of the prioritization of any generated exceptions, see section D1.13.2 (Synchronous exception prioritization) in the ARM® Architecture Reference Manual, ARMv8, for ARMv8-A architecture profile. Subject to the prioritization rules, the following traps and enables are applicable when accessing this register.

When EL2 is implemented and is using AArch64 and SCR_EL3.NS==1 :

When EL3 is implemented and is using AArch64 :




28/09/2017 08:24

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