Coprocessor 15
2-23
MPU Subsystem
2.6.2.5
Context Switch (or PID: Process Identifier) Register
The PID register is used in Windows CE mode only. The register is used in con-
junction with the fast-context switch hardware support and is only used when
the Windows CE mode bit is enabled. More information is available upon
request.
2.6.2.6
TI Operations
Register 15 controls specific TI features. Opcode_2 and CRm select the
different available registers or operations.
The wait-for-interrupt is write-only. The cache size is hard-wired and read-only.
The others are read/write registers.
Table 2–13. TI Operations
Function
Opcode_2
CRm
Rd
Instruction
Set TI925T configuration
0b000
0b0001
Value
MCR p15, 0, Rd, c15, c1, 0
Read TI925T configuration
0b000
0b0001
Value
MRC p15, 0, Rd, c15, c1, 0
Read I_max
0b000
0b0010
Value
MRC p15, 0, Rd, c15, c2, 0
Set I_max
0b000
0b0010
Value
MCR p15, 0, Rd, c15, c2, 0
Read I_min
0b000
0b0011
Value
MRC p15, 0, Rd, c15, c3, 0
Set I_min
0b000
0b0011
Value
MCR p15, 0, Rd, c15, c3, 0
Read thread-ID
0b000
0b0100
Value
MRC p15, 0, Rd, c15, c4, 0
Set thread-ID
0b000
0b0100
Value
MCR p15, 0, Rd, c15, c4, 0
TI925T_status
0b000
0b1000
Value
MRC p15, 0, Rd, c15, c8, 0
Wait-for-interrupt
0b010
0b1000
Ignored
MCR p15, 0, Rd , c15, c8,2
Note:
Required for backward code compatibility. Developers must use the wait-for-interrupt described in register 7.
All control bits except L (lock enable) and O (OS type) are set to zero upon
reset.
Table 2–14. TI925T Configuration Register
Bit
Name
Value
Function
7
S
Instruction cache streaming disable
0
I-cache is set in streaming mode. This is the default state after reset.
1
I-cache is set in nonstreaming mode.