EDVIDSR, External Debug Virtual Context Sample Register

The EDVIDSR characteristics are:

Purpose

Contains sampled values captured on reading EDPCSR[31:0].

This register is part of the Debug registers functional group.

Usage constraints

This register is accessible as follows:

OffDLKOSLKDefault
ErrorErrorErrorRO

Configuration

EDVIDSR is in the Core power domain.

Fields in this register reset to architecturally UNKNOWN values. These apply only on a Cold reset. The register is not affected by a Warm reset and is not affected by an External debug reset.

Implemented only if the OPTIONAL PC Sample-based Profiling Extension is implemented and ARMv8.2-PCSample is not implemented. If ARMv8.2-PCSample is implemented, this register is RES0 and the architecture defines the functionality in PMPCSR, PMCID2SR, and PMVIDSR.

If EL2 is not implemented and EL3 is not implemented, it is IMPLEMENTATION DEFINED whether EDVIDSR is implemented.

Attributes

If ARMv8.1-VHE is implemented, the format of this register differs depending on the value of EDSCR.SC2.

Field descriptions

The EDVIDSR bit assignments are:

When ARMv8.1-VHE is not implemented:

313029282726252423222120191817161514131211109876543210
NSE2E3HV00000000000000000000VMID

NS, bit [31]

Non-secure state sample. Indicates the Security state associated with the most recent EDPCSR sample.

If EL3 is not implemented, this bit indicates the Effective value of SCR.NS.

When this register has an architecturally-defined reset value, this field resets to a value that is architecturally UNKNOWN.

E2, bit [30]

Exception level 2 status sample. Indicates whether the most recent EDPCSR sample was associated with EL2.

If EL2 is not implemented, this bit is RES0.

When this register has an architecturally-defined reset value, this field resets to a value that is architecturally UNKNOWN.

E3, bit [29]

Exception level 3 status sample. Indicates whether the most recent EDPCSR sample was associated with EL3 using AArch64.

If EDVIDSR.NS == 1 or the PE was in AArch32 state when EDPCSRlo (EDPCSR[31:0]) was read, this bit is 0.

If EL3 is not implemented, this bit is RES0.

When this register has an architecturally-defined reset value, this field resets to a value that is architecturally UNKNOWN.

HV, bit [28]

EDPCSRhi (EDPCSR[63:32]) valid. Indicates whether bits [63:32] of the most recent EDPCSR sample might be nonzero:

HVMeaning
0

Bits[63:32] of the most recent EDPCSR sample are zero.

1

Bits[63:32] of the most recent EDPCSR sample might be nonzero.

An EDVIDSR.HV value of 1 does not mean that the value of EDPCSRhi is nonzero. An EDVIDSR.HV value of 0 is a hint that EDPCSRhi (EDPCSR[63:32]) does not need to be read.

When this register has an architecturally-defined reset value, this field resets to a value that is architecturally UNKNOWN.

Bits [27:8]

Reserved, RES0.

VMID, bits [7:0]

VMID sample. The VMID associated with the most recent EDPCSRlo (EDPCSR[31:0]) sample.

If the value of EDVIDSR.NS is 0 or the value of EDVIDSR.E2 is 1 this field is RES0.

If EL2 is not implemented, then this field is RES0.

When this register has an architecturally-defined reset value, this field resets to a value that is architecturally UNKNOWN.

When ARMv8.1-VHE is implemented and EDSCR.SC2 == 0:

313029282726252423222120191817161514131211109876543210
NSE2E3HV000000000000VMID

This format applies in all ARMv8.0 implementations.

NS, bit [31]

Non-secure state sample. Indicates the Security state associated with the most recent EDPCSR sample.

If EL3 is not implemented, this bit indicates the Effective value of SCR.NS.

When this register has an architecturally-defined reset value, this field resets to a value that is architecturally UNKNOWN.

E2, bit [30]

Exception level 2 status sample. Indicates whether the most recent EDPCSR sample was associated with EL2.

If EL2 is not implemented, this bit is RES0.

When this register has an architecturally-defined reset value, this field resets to a value that is architecturally UNKNOWN.

E3, bit [29]

Exception level 3 status sample. Indicates whether the most recent EDPCSR sample was associated with EL3 using AArch64.

If EDVIDSR.NS == 1 or the PE was in AArch32 state when EDPCSRlo (EDPCSR[31:0]) was read, this bit is 0.

If EL3 is not implemented, this bit is RES0.

When this register has an architecturally-defined reset value, this field resets to a value that is architecturally UNKNOWN.

HV, bit [28]

EDPCSRhi (EDPCSR[63:32]) valid. Indicates whether bits [63:32] of the most recent EDPCSR sample might be nonzero:

HVMeaning
0

Bits[63:32] of the most recent EDPCSR sample are zero.

1

Bits[63:32] of the most recent EDPCSR sample might be nonzero.

An EDVIDSR.HV value of 1 does not mean that the value of EDPCSRhi is nonzero. An EDVIDSR.HV value of 0 is a hint that EDPCSRhi (EDPCSR[63:32]) does not need to be read.

When this register has an architecturally-defined reset value, this field resets to a value that is architecturally UNKNOWN.

Bits [27:16]

Reserved, RES0.

VMID, bits [15:0]

VMID sample. The VMID associated with the most recent EDPCSRlo (EDPCSR[31:0]) sample.

When this register has an architecturally-defined reset value, this field resets to a value that is architecturally UNKNOWN.

When ARMv8.1-VHE is implemented and EDSCR.SC2 == 1:

313029282726252423222120191817161514131211109876543210
CONTEXTIDR_EL2

CONTEXTIDR_EL2, bits [31:0]

Context ID.

When this register has an architecturally-defined reset value, this field resets to a value that is architecturally UNKNOWN.

When ARMv8.2-PCSample is implemented:

313029282726252423222120191817161514131211109876543210
00000000000000000000000000000000

Bits [31:0]

Reserved, RES0.

Accessing the EDVIDSR

EDVIDSR can be accessed through the external debug interface:

ComponentOffset
Debug 0x0A8



02/05/2017 15:43

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