AMD LX 600@0.7W User Manual
160
AMD Geode™ LX Processors Data Book
CPU Core Register Descriptions
33234H
32
WBDIS
Write Buffer Disable. Disabling the write buffer forces stores to be sent directly from the
output of the store queue to the bus controller. Enabling the write buffer allows memory
stores to be buffered, with or without combining based on region properties.
output of the store queue to the bus controller. Enabling the write buffer allows memory
stores to be buffered, with or without combining based on region properties.
0: Enable write buffer. (Default)
1: Disable write buffer.
Note:
If write allocate is used in any region configuration register, then the write buffer
must be enabled.
must be enabled.
31:16
LSLOCK
Load/Store Lockout. Bit mask of ways which cannot be allocated or replaced on a load
or store miss. If all ways are locked, caching is effectively disabled, though the cache will
still be interrogated. Use DCDIS (bit 8) to disable the interrogations as well. Note that this
field has been increased from 4 bits in the AMD Geode™ GX processor to 16 bits to
allow for the new 16 way cache). (Default = 0)
or store miss. If all ways are locked, caching is effectively disabled, though the cache will
still be interrogated. Use DCDIS (bit 8) to disable the interrogations as well. Note that this
field has been increased from 4 bits in the AMD Geode™ GX processor to 16 bits to
allow for the new 16 way cache). (Default = 0)
15
NOLOCKEVCT
Do Not Evict Clean Lines Locked by LSLOCK. When this bit is 1, clean lines locked by
LSLOCK will not be evicted into the L2 cache upon replacement. This feature is intended
to be used with the auto-prefetch mechanism to prevent auto-prefetched data from get-
ting into the L2 cache. In this case, LSLOCK and APFLOCK would divide the ways of the
cache into prefetched and non-prefetched ways. Only the non-prefetched ways would be
evicted into the L2. (Default = 0)
LSLOCK will not be evicted into the L2 cache upon replacement. This feature is intended
to be used with the auto-prefetch mechanism to prevent auto-prefetched data from get-
ting into the L2 cache. In this case, LSLOCK and APFLOCK would divide the ways of the
cache into prefetched and non-prefetched ways. Only the non-prefetched ways would be
evicted into the L2. (Default = 0)
14
EVCTONRPL
Evict Clean Lines on Replacement. This bit should be set when an external L2 cache is
operating in Victim mode.
operating in Victim mode.
0: Invalidate clean cache lines when replaced, do not evict. (Default)
1: Evict clean cache lines when they are replaced.
13
NOFTTBRES
No Page Fault. Do not page fault if any reserved bits are set in the Directory Table
Entries (DTE)/Page Table Entries (PTE).
Entries (DTE)/Page Table Entries (PTE).
0: Take the page fault. (Default)
1: Do not take the page fault.
12
DTCNINV
Do Not Invalidate DTE Cache Entry. Do not invalidate DTE cache entry on INVLPG
instruction. Entire DTE cache is still flushed on a store into the directory page.
instruction. Entire DTE cache is still flushed on a store into the directory page.
0: Invalidate DTE cache entry if INVLPG hits. (Default)
1: Do not invalidate DTE cache entry on INVLPG.
11
P4MDIS
Disable 4M PTE Cache.
0: Allow 4M PTEs to be cached. (Default)
1: Do not cache 4M PTEs and flush any existing entries.
10
DTCDIS
Disable DTE Cache.
0: Allow DTEs to be cached. (Default)
1: Do not cache DTEs, flush any existing entries.
9
L2TDIS
Disable L2 TLB. Contents will not be modified.
0: Interrogate and allocate entries in the L2 TLB. (Default)
1: L2 TLB will always generate a miss.
8
DCDIS
Disable Data Cache (completely). Contents will not be modified. Intended to be used
for array testing or in case of cache array failure.
for array testing or in case of cache array failure.
0: Use standard x86 cacheability rules. (Default)
1: Data cache will always generate a miss.
DM_CONFIG0_MSR Bit Descriptions (Continued)
Bits
Name
Description