2-4 Intel® PXA255 Processor Developer’s Manual
System Architecture
2.2.5 Coprocessor 15 Register 1 - P-Bit
Bit 1 of this register is defined as the Page Ta ble Memory Attribute bit or P-bit. It is not
implemented in the processor and must be written as zero. Similarly, the P-bit in the page table
descriptor in the MMU is not implemented and must be written to zero.
Table 2-2. ID Bit Definitions
CP15 Register 0 ID CP15
Bit 31 30 29 28 27 26 25 24 23 22 21 20 19 18 17 16 15 14 13 12 11 10 9876543210
Implementation
Trademark
Architecture
Version
Core
generation
Core
Revision
Product
Number
Product
Revision
Reset 01101001000001010010000100000000
[31:24] Implementation
Trademark
Implementation trademark.
0x69 Intel® Corporation.
[23:16] Architecture
Version
ARM* Architecture version of the core.
0x05 ARM* Architecture version 5TE
[15:13] Core Generation
This field is updated when new sets of features are added to the core. This
allows software that is dependant on core features to target a specific core.
Core generation:
0b001 Intel® XScale™ core
[12:10] Core Revision
This field is updated each time a core is revised. Differences may include
errata, software workarounds, etc.
Core revision:
0b000 First version of the core.
0b010 Third version of the core.
0b011 Fourth version of the core.
[9:4] Product Number Product Number
0b010000 – PXA255 processor
[3:0] Product Revision
This field tracks the different steppings for each ASSP.
Product Revision
0b0110 A0 Stepping
Table 2-3. PXA255 Processor ID Values
Stepping ARM ID JTAG ID
A0 0x6905_2D06 0x6926_4013