Intel 80200, Processor 7.2.10 Register 9: Cache Lock Down

7-14 March, 2003 Developer’s Manual
Intel® 80200 Processor based on Intel® XScale™ Microarchitecture
Configuration
7.2.10 Register 9: Cache Lock Down
Register 9 is used for locking down entries into the instruction cache and data cache. (The protocol
for locking down entries can be found in Chapter6, “Data Cache”.)
Table 7- 14 shows the command for locking down entries in the instruction cache, instruction TLB,
and data TLB. The entry to lock is specified by the virtual address in Rd. The data cache locking
mechanism follows a different procedure than the others. The data cache is placed in lock down
mode such that all subsequent fills to the data cache result in that line being locked in, as controlled
by Table 7 -15.
Lock/unlock operations on a disabled cache have an undefined effect. This register should be
accessed as write-only. Reads from this register, as with an MRC, have an undefined effect.
Table 7-14. Cache Lockdown Functions
Function opcode_2 CRm Data Instruction
Fetch and Lock I cache line 0b000 0b0001 MVA MCR p15, 0, Rd, c9, c1, 0
Unlock Instruction cache 0b001 0b0001 Ignored MCR p15, 0, Rd, c9, c1, 1
Read data cache lock register 0b000 0b0010 Read lock mode
value MRC p15, 0, Rd, c9, c2, 0
Write data cache lock register 0b000 0b0010 Set/Clear lock
mode MCR p15, 0, Rd, c9, c2, 0
Unlock Data Cache 0b001 0b0010 Ignored MCR p15, 0, Rd, c9, c2, 1
Table 7-15. Data Cache Lock Register
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
L
reset value: writeable bits set to 0
Bits Access Description
31:1 Read-unpredictable / Write-as-Zero Reserved
0 Read-unpredictable / Write
Data Cache Lock Mode (L)
0 = No locking occurs
1 = Any fill into the data cache while this bit is set gets
locked in