TRCPIDR4

This register is present only when FEAT_ETE is implemented and FEAT_TRC_EXT is implemented. Otherwise, direct accesses to TRCPIDR4 are RES0.

Attributes

Field descriptions

Bits [31:8]

SIZE, bits [7:4]

Size of the component.

The value of this field is an IMPLEMENTATION DEFINED choice of:

SIZE	Meaning
0b0000	One of the following is true: The component uses a single 4KB block. The component uses an IMPLEMENTATION DEFINED number of 4KB blocks.
0b0001..0b1111	The component occupies 2^{TRCPIDR4.SIZE} 4KB blocks.

SIZE

Meaning

0b0000

One of the following is true:

The component uses a single 4KB block.
The component uses an IMPLEMENTATION DEFINED number of 4KB blocks.

0b0001..0b1111

The component occupies 2^{TRCPIDR4.SIZE} 4KB blocks.

Using this field to indicate the size of the component is deprecated. This field might not correctly indicate the size of the component. Arm recommends that software determine the size of the component from the Unique Component Identifier fields, and other IMPLEMENTATION DEFINED registers in the component.

This field has the value 0b0000.

Access to this field is RO.

DES_2, bits [3:0]

Designer, JEP106 continuation code.

JEP106 identification and continuation codes, which are stored as follows:

TRCPIDR1.DES_0: JEP106 identification code bits[3:0].
TRCPIDR2.DES_1: JEP106 identification code bits[6:4].
TRCPIDR4.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 JEDEC 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 TRCPIDR4

TRCPIDR4 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

TRCPIDR4, Trace Peripheral Identification Register 4

Purpose