Programmer’s Model
2-10 Copyright © 2001-2003 ARM Limited. All rights reserved. ARM DDI0198D
Assoc The Assoc field determines the cache associativity in conjunction with
the M bit.
M bit The multiplier bit determines the cache size and cache associativity
values in conjunction with the Size and Assoc fields. If the cache is
present, M must be set to 0. If the cache is absent, M must be set to 1. For
the ARM926EJ-S processor, M is always set to 0.
Len The Len field determines the line length of the cache.
The size of the cache is determined by the Size field and the M bit. The M bit is 0 for
the DCache and ICache. The Size field is bits [21:18] for the DCache and bits [9:6] for
the ICache. The minimum size of each cache is 4KB, and the maximum size is 128KB.
Table 2-7 shows the cache size encoding.
The associativity of the cache is determined by the Assoc field and the M bit. The M bit
is 0 for the DCache and ICache. The Assoc field is bits [17:15] for the DCache and bits
[5:3] for the ICache. Table 2-8 shows the cache associativity encoding.
Table 2-7 Cache size encoding (M=0)
Size field Cache size
b0011 4KB
b0100 8KB
b0101 16KB
b0110 32KB
b0111 64KB
b1000 128KB
Table 2-8 Cache associativity encoding (M=0)
Assoc field Associativity
b010 4-way
Other values Reserved
To Next Page
