Programmer’s Model
ARM DDI0198D Copyright © 2001-2003 ARM Limited. All rights reserved. 2-11
The line length of the cache is determined by the Len field. The Len field is bits [13:12]
for the DCache and bits [1:0] for the ICache. Table 2-9 shows the line length encoding.
The cache type register values for an ARM926EJ-S processor with the following
configuration are shown in Table 2-10:
• separate instruction and data caches
• DCache size = 8KB, ICache size = 16KB
• associativity = 4-way
• line length = eight words
• caches use write-back, register 7 for cache cleaning, and Format C for cache
lockdown.
See Cache Lockdown Register c9 on page 2-26 for more details on Format C for cache
lockdown.
Table 2-9 Line length encoding
Len field Cache line length
b10 8 words (32 bytes)
Other values Reserved
Table 2-10 Example Cache Type Register format
Function Register bits Value
Reserved [31:29] b000
Ctype [28:25] b1110
S [24] b1 = Harvard cache
Dsize Reserved [23:22] b00
Size [21:18] b0100 = 8KB
Assoc [17:15] b010 = 4-way
M[14] b0
Len [13:12] b10 = 8 words per line (32 bytes)