You copied the Doc URL to your clipboard.

EDPIDR1, External Debug Peripheral Identification Register 1

The EDPIDR1 characteristics are:


Provides information to identify an external debug component.

For more information see 'About the Peripheral identification scheme' in the Arm® Architecture Reference Manual, Armv8, for Armv8-A architecture profile, section H8 (About the External Debug Registers).


It is IMPLEMENTATION DEFINED whether EDPIDR1 is implemented in the Core power domain or in the Debug power domain.

Implementation of this register is OPTIONAL.

If ARMv8.3-DoPD is implemented, this register is in the Core power domain. If ARMv8.3-DoPD is not implemented, this register is in the Debug power domain.

This register is required for CoreSight compliance.


EDPIDR1 is a 32-bit register.

Field descriptions

The EDPIDR1 bit assignments are:


Bits [31:8]

Reserved, RES0.

DES_0, bits [7:4]

Designer, least significant nibble of JEP106 ID code. For Arm Limited, this field is 0b1011.

PART_1, bits [3:0]

Part number, most significant nibble.

Accessing the EDPIDR1

EDPIDR1 can be accessed through the external debug interface:


This interface is accessible as follows:

  • When ARMv8.3-DoPD is not implemented or IsCorePowered() accesses to this register are RO.
  • Otherwise accesses to this register generate an error response.