EDPIDR4

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EDPIDR4, External Debug Peripheral Identification Register 4

Purpose

Configuration

When FEAT_DoPD is implemented, EDPIDR4 is in the Core power domain. Otherwise, EDPIDR4 is in the Debug power domain.

Attributes

Field descriptions

Bits [31:8]

SIZE, bits [7:4]

Size of the component. Log₂ of the number of 4KB pages from the start of the component to the end of the component ID registers.

Reads as 0b0000.

Access to this field is RO.

DES_2, bits [3:0]

Designer, JEP106 continuation code.

The JEP106 identification and continuation codes are stored as follows:

EDPIDR1.DES_0: JEP106 identification code bits[3:0].
EDPIDR2.DES_1: JEP106 identification code bits[6:4].
EDPIDR4.DES_2: JEP106 continuation code.

These codes indicate the designer of the component and not the implementer, except where the two are the same. To obtain a number, or to see the assignment of these codes, contact JEDEC http://www.jedec.org.

A JEP106 identification and continuation code takes the following form:

A sequence of zero or more numbers, all having the value 0x7F.
A following 8-bit number, that is not 0x7F, and where bit[7] is an odd parity bit.

The parity bit in the JEP106 identification code is not included.

Note

For example, Arm Limited is assigned the code 0x7F 0x7F 0x7F 0x7F 0x3B.

The continuation code is the number of times 0x7F appears before the final number. For example, a component designed by Arm Limited has the code 0x4.
The identification code is bits[6:0] of the final number. For example, a component designed by Arm Limited has the code 0x3B.

This field has an IMPLEMENTATION DEFINED value.

Access to this field is RO.

Accessing EDPIDR4

EDPIDR4 can be accessed through the external debug interface:

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																								SIZE				DES_2