EDPIDR4, External Debug Peripheral Identification Register 4
The EDPIDR4 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).
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.
EDPIDR4 is a 32-bit register.
The EDPIDR4 bit assignments are:
SIZE, bits [7:4]
Size of the component. RAZ. Log2 of the number of 4KB pages from the start of the component to the end of the component ID registers.
DES_2, bits [3:0]
Designer, JEP106 continuation code, least significant nibble. For Arm Limited, this field is 0b0100.
Accessing the EDPIDR4
EDPIDR4 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.