| Copyright © 2009, 2010 ARM. All rights reserved. | ARM DDI 0433B |
| Non-Confidential | ID101810 |
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| Home > System Control > About system control > System feature registers |
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The system feature registers specify:
Processor features
Debug features
Memory model features.
You can access these registers with the following CP15 instruction:
MRC p15, 0, <Rd>, c0, c1, {0-7} ; reads feature version registers
Depending on the Opcode_2 value, the accessed register is:
Opcode_2 = 0 for ID_PFR0, Processor Feature Register 0
Opcode_2 = 1 for ID_PFR1, Processor Feature Register 1
Opcode_2 = 2 for ID_DFR0, Debug Feature Register 0
Opcode_2 = 3 Reserved
Opcode_2 = 4 for ID_MMFR0, Memory Model Feature Register 0
Opcode_2 = 5 for ID_MMFR1, Memory Model Feature Register 1
Opcode_2 = 6 for ID_MMFR2, Memory Model Feature Register 2
Opcode_2 = 7 for ID_MMFR3, Memory Model Feature Register 3.
The Reserved Opcode_2 value, Opcode_2=3, reads as zero.
| Copyright © 2009, 2010 ARM. All rights reserved. | ARM DDI 0433B |
| Non-Confidential | ID101810 |
| PDF version | |
| Home > System Control > About system control > System feature registers |