ADSP-BF535 Blackfin Processor Hardware Reference
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Memory
The Valid bit indicates the state of a cache line. A cache line is always
valid or invalid:
• Invalid cache lines have their Valid bit cleared, indicating the line
will be ignored during an address tag compare operation.
• Valid cache lines have their Valid bit set, indicating the line con-
tains valid instruction/data that is consistent with the source
memory.
The tag and data components of a cache line are illustrated in
Figure 6-7
.
Cache Hits and Misses
A cache hit occurs when the address for an instruction fetch request from
the core matches a valid entry in the cache. Specifically, a cache hit is
determined by comparing the upper 18 bits and bits 11 and 10 of the
instruction fetch address to the address tags of valid lines currently stored
in a cache set. The cache set is selected, using bits 9 through 5 of the
instruction fetch address. If the address tag compare operation results in a
match, a cache hit occurs. If the address tag compare operation does not
result in a match, a cache miss occurs.
Figure 6-7. Cache Line – Tag and Data Portions
TAG
LRU
V
TAG — 20-BIT ADDRESS TAG
LRU — LRU STATE
V — VALID BIT
WD 3
WD 2
WD 1
WD 0
WD — 64-BIT DATA WORD
Содержание ADSP-BF535 Blackfin
Страница 80: ...Development Tools 1 26 ADSP BF535 Blackfin Processor Hardware Reference...
Страница 312: ...Working With Memory 6 86 ADSP BF535 Blackfin Processor Hardware Reference...
Страница 332: ...System Interfaces 7 20 ADSP BF535 Blackfin Processor Hardware Reference...
Страница 360: ...Dynamic Power Management Controller 8 28 ADSP BF535 Blackfin Processor Hardware Reference...
Страница 446: ...Beginning and Ending an SPI Transfer 10 40 ADSP BF535 Blackfin Processor Hardware Reference...
Страница 522: ...Timing Examples 11 76 ADSP BF535 Blackfin Processor Hardware Reference...
Страница 562: ...IrDA Support 12 40 ADSP BF535 Blackfin Processor Hardware Reference...
Страница 608: ...PCI I O Issues 13 46 ADSP BF535 Blackfin Processor Hardware Reference...
Страница 672: ...References 14 64 ADSP BF535 Blackfin Processor Hardware Reference...
Страница 810: ...SDRAM Controller SDC 18 86 ADSP BF535 Blackfin Processor Hardware Reference...
Страница 811: ...ADSP BF535 Blackfin Processor Hardware Reference 18 87 External Bus Interface Unit...
Страница 812: ...SDRAM Controller SDC 18 88 ADSP BF535 Blackfin Processor Hardware Reference...
Страница 860: ...DMA Bus Debug Registers 20 30 ADSP BF535 Blackfin Processor Hardware Reference...
Страница 908: ...SDRAM Controller External Bus Interface Unit B 36 ADSP BF535 Blackfin Processor Hardware Reference...