Coprocessor 15
2-12
Table 2–4. Reading From CP15 Register 0
Function
Opcode_2
CRm
Rd
Instruction
Read ID
†
0bXXX
0bXXXX
TI925T ID
MRC p15, 0, Rd, c0, c0, 0
Read CIR
0b001
0b0000
Cache info
MRC p15, 0, Rd, c0, c0, 1
† All opcodes [opcode_2,CRm] except [1,0] return the TI925T ID.
Table 2–5. CP15 ID Register
Bit
Name
Function
31–24
Implementers
Contains the ASCII code of the implementer trademark (0x54 = Texas
Instruments)
23–16
Architecture version
Contains the architecture version (0x02 Version v4T)
15–4
Part number
Contains a 3-digit part number in binary-coded decimal format.The OS bit
O in the TI925T configuration register sets the value of these fields as
follows:
915 in TI925T mode
925 in Windows CE mode
3–0
Reserved
Contains the microprocessor revision number 2
Table 2–6. CP15 Cache Information Register (CIR)
Bit
Name
Value
Function
31–29
Reserved
0
Read as 0.
28–25
Cache type
Cache type: read as 0010. The cache provides clean-cache
entry and flush-cache-entry with a cache index in addition of the
operations with virtual address (also called clean-cache-step or
flush-cache-step). The format of the clean-cache-entry is given
in the Register 7: Cache Operations section.
24
ID
0
Unified I-/D-cache
1
Harvard cache
23–21
Reserved
0
Read as 0.
20–18
D-cache information
Base value of D-cache size (same format as for I-cache)
17–15
D-cache information
Base value of D-cache associativity (same format as for I-cache)