Intel 80200 Computer Hardware User Manual


 
7-8 March, 2003 Developers Manual
Intel
®
80200 Processor based on Intel
®
XScale
Microarchitecture
Configuration
The mini-data cache attribute bits, in the Intel
®
80200 processor Control Register, are used to
control the allocation policy for the mini-data cache and whether it uses write-back caching or
write-through caching.
The configuration of the mini-data cache should be setup before any data access is made that may
be cached in the mini-data cache. Once data is cached, software must ensure that the mini-data
cache has been cleaned and invalidated before the mini-data cache attributes can be changed.
Table 7-7. Auxiliary Control 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
MD PK
reset value: writeable bits set to 0
Bits Access Description
31:6
Read-Unpredictable /
Write-as-Zero
Reserved
5:4 Read / Write
Mini Data Cache Attributes (MD)
All configurations of the Mini-data cache are cacheable,
stores are buffered in the write buffer and stores are
coalesced in the write buffer as long as coalescing is
globally enabled (bit 0 of this register).
0b00 = Write back, Read allocate
0b01 = Write back, Read/Write allocate
0b10 = Write through, Read allocate
0b11 = Unpredictable
3:2
Read-Unpredictable /
Write-as-Zero
Reserved
1 Read / Write
Page Table Memory Attribute (P)
If set, page table accesses are protected by ECC. See
Chapter 11, Bus Controller for more information.
0 Read / Write
Write Buffer Coalescing Disable (K)
This bit globally disables the coalescing of all stores in the
write buffer no matter what the value of the Cacheable
and Bufferable bits are in the page table descriptors.
0 = Enabled
1 = Disabled