NO:
W90P710 Programming Guide
VERSION:
2.1
PAGE:
41
The above information is the exclusive intellectual property of Winbond Electronics and shall not be disclosed,
distributed or reproduced without permission from Winbond.
Table No.: 1200-0003-07-A
z
The code that executes load and lock operation should be held in a non-cacheable area of
memory.
z
The cache should be enabled and interrupts should be disabled.
z
Flushed the cache before execute load and lock to ensure that the data to be locked down is
not already in the cache.
3.4.6 Cache Unlock
The unlock operation is used to unlock previously locked cache lines. The cache controller
provides two unlock command, unlock line and unlock all.
The unlock line operation is performed on a cache line granularity. In case the line is found in the
cache, it is unlocked and starts to operate as a regular valid cache line. In case the line is not found in
the cache, no operation is done and the command terminates with no exception. To unlock one line,
write the address of the line to be unlocked into the
CAHADR
Register, and then set the
ULKS
and
ICAH
bits in the CAHCON register for I-cache or set the
ULKS
and
DCAH
bits for D-cache.
The unlock all operation is performed on all cache lines of I-Cache or D-Cache. In case a line is
locked, it is unlocked and starts to operate as regular valid cache line. In case a line is not locked or if
it is invalid, no operation is performed. To unlock the whole instruction cache, set the
ULKA
and
ICAH
bits. To unlock the whole data cache, set the
ULKA
and
DCAH
bits.