Intel® IXP42X Product Line of Network Processors and IXC1100 Control Plane Processor
September 2006 DM
Order Number: 252480-006US 75
Intel XScale® Processor—Intel® IXP42X product line and IXC1100 control plane processors
3.5.1 CP15 Registers

Tabl e 9 lists the CP15 registers implemented in Intel® IXP42X Product Line of Network

Processors and IXC1100 Control Plane Processor.

Table 8. LDC/STC Format when Accessing CP14

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
cond 1 1 0 P U N W L Rn CRd cp_num 8_bit_word_offset
Bits Description Notes
31:28 cond - ARM condition codes -
24:23,21 P, U, W - specifies 1 of 3 addressing modes
identified by addressing mode 5 in the ARM*
Architecture Reference Manual.-
22 N - should be 0 for CP14 coprocessors. Setting
this bit to 1 has will have an undefined effect.
20 L - Load or Store
0 = STC
1 = LDC -
19:16 Rn - specifies the base register -
15:12 CRd - specifies the coprocessor register -
11:8 cp_num - coprocessor number
Intel XScale processor defines the following:
0b1111 = Undefined Exception
0b1110 = CP14
Note: Mappings are implementation defined
for all coprocessors below CP13.
Access to unimplemented
coprocessors (as defined by the
cpConfig bus) cause exceptions.
7:0 8-bit word offset -

Table 9. CP15 Registers (Sheet 1 of 2)

Register
(CRn) Opcode_2 Access Description
0 0 Read / Write-Ignored ID
0 1 Read / Write-Ignored Cache Type
1 0 Read / Write Control
1 1 Read / Write Auxiliary Control
20 Read / Write Translation Table Base
3 0 Read / Write Domain Access Control
4 - Unpredictable Reserved
5 0 Read / Write Fault Status
6 0 Read / Write Fault Address
7 0 Read-unpredictable / Write Cache Operations
8 0 Read-unpredictable / Write TLB Operations
9 0 Read / Write Cache Lock Down
10 0 Read-unpredictable / Write TLB Lock Down