Memory Architecture
6-46
ADSP-BF535 Blackfin Processor Hardware Reference
The ADSP-BF535 processor data cache supports hit-under-a-store miss,
and hit-under-a-prefetch miss. In other words, on a write-miss or execu-
tion of a
PREFETCH
instruction that misses the cache (and is to a cacheable
region), the instruction pipeline does not stall on the miss. Furthermore, a
subsequent load or store instruction can hit in the L1 cache while the
line-fill completes.
Interrupts of sufficient priority (relative to the current context) cancel a
stalled load instruction. Consequently, if the load operation misses the L1
Data Memory cache and generates a high latency line fill operation on the
system interface, it is possible to interrupt the core, causing it to begin
processing a different context. The system access to fill the cache line is
not cancelled, and the data cache is updated with the new data before any
further cache miss operations to the respective data bank are serviced. For
more information see
“Exceptions” on page 4-38
.
Cache Write Method
Cache write memory operations can be implemented by using either a
write through method or a write back method:
• For each store operation, write through caches initiate a write to L2
memory immediately upon the write to cache.
• If the cache line is replaced or explicitly flushed by software, the
contents of the cache line are invalidated rather than written back
to L2 memory.
• A write back cache does not write to L2 memory until the line is
replaced by a load operation that needs the line.
The L1 Data Memory employs a full cache line width copyback buffer on
each data bank. In addition, a four-entry write buffer in the L1 Data
Memory accepts all stores with cache inhibited or store through protec-
tion. An
SSYNC
instruction flushes the write buffer.
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...