Cortex™-A8 Technical Reference Manual 3.2.22. c0, Silicon ID Register

3.2.22. c0, Silicon ID Register

The purpose of the Silicon ID Register is to enable software to identify the silicon manufacturer and revision. The reset value of this register is the SILICONID[31:0] input.

The Silicon ID Register is:

a read-only register common for Secure and Nonsecure states
accessible in privileged modes only.

Figure 3.17 shows the bit arrangement of the Silicon ID Register.

Figure 3.17. Silicon ID Register format

Table 3.39 shows how the bit values correspond with the Silicon ID Register functions.

Table 3.39. Silicon ID Register bit functions

Bits	Field	Function
[31:24]	Implementor	This field contains a code that identifies the silicon manufacturer. ARM assigns this code.
[23:16]	Feature	This field is implementation-defined.
[15:8]	-	Reserved, RAZ.
[7:4]	Major revision	This field is implementation-defined.
[3:0]	Minor revision	This field is implementation-defined.

Table 3.40 shows the results of attempted access for each mode.

Table 3.40. Results of access to the Silicon ID Register^[20]

Secure privileged		Nonsecure privileged		Secure User		Nonsecure User
Read	Write	Read	Write	Read	Write	Read	Write
Data	Undefined	Data	Undefined	Undefined	Undefined	Undefined	Undefined

To access the Silicon ID Register, read CP15 with:

MRC p15, 1, <Rd>, c0, c0, 7 ; Read Silicon ID Register

Copyright © 2006-2008 ARM Limited. All rights reserved.	ARM DDI 0344E
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