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Cortex-A8 Technical Reference Manual - ARM Information Center

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System Control Coprocessor<br />

Figure 3-18 Cache Size Identification Register format<br />

Table 3-41 shows how the bit values correspond with the Cache Size Identification Register<br />

functions. See Table 3-42 for valid bit field encodings.<br />

Table 3-42 shows the individual bit field and complete register encodings for the Cache Size<br />

Identification Register. Use this to match the cache size and level of cache set by the Cache Size<br />

Selection Register (CSSR). See c0, Cache Size Selection Register on page 3-43.<br />

CSSR Size<br />

31 30 29 28 27 13 12 3 2 0<br />

WT<br />

WB<br />

RA<br />

WA<br />

Complete<br />

register<br />

encoding<br />

NumSets Associativity<br />

<strong>ARM</strong> DDI 0344K Copyright © 2006-2010 <strong>ARM</strong> Limited. All rights reserved. 3-42<br />

ID060510 Non-Confidential<br />

Line<br />

Size<br />

Table 3-41 Cache Size Identification Register bit functions<br />

Bits Field Function<br />

[31] WT Indicates support available for write-through:<br />

0 = write-through not supported<br />

1 = write-through supported.<br />

[30] WB Indicates support available for write-back:<br />

0 = write-back not supported<br />

1 = write-back supported.<br />

[29] RA Indicates support available for read allocation:<br />

0 = read allocation not supported<br />

1 = read allocation supported.<br />

[28] WA Indicates support available for write allocation:<br />

0 = write allocation not supported<br />

1 = write allocation supported.<br />

[27:13] NumSets Indicates number of sets - 1.<br />

[12:3] Associativity Indicates number of ways - 1.<br />

[2:0] LineSize Indicates (log2(number of words in cache line)) - 2.<br />

Table 3-42 Encodings of the Cache Size Identification Register<br />

Register bit field encoding<br />

WT WB RA WA NumSets Associativity LineSize<br />

0x0 16KB 0xE007E01A 1 1 1 0 0x003F 0x3 0x2<br />

32KB 0xE00FE01A 1 1 1 0 0x007F 0x3 0x2<br />

0x1 16KB 0x2007E01A 0 0 1 0 0x003F 0x3 0x2<br />

32KB 0x200FE01A 0 0 1 0 0x007F 0x3 0x2

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