ADSP-BF53x/BF56x Blackfin Processor Programming Reference
6-27
Memory
By default after reset, all L1 Data Memory serves as SRAM. The
DMC[1:0]
bits can be used to reserve portions of this memory to serve as cache
instead. Reserving memory to serve as cache does not enable L2 memory
accesses to be cached. To do this, CPLBs must also be enabled (using the
ENDCPLB
bit) and CPLB descriptors (registers
DCPLB_DATAx
and
DCPLB_ADDRx
) must specify chosen memory pages as cache-enabled.
By default after reset, cache and CPLB address checking is disabled.
L
To ensure proper behavior and future compatibility, all reserved
bits in this register must be set to 0 whenever this register is
written.
L1 Data SRAM
Accesses to SRAM do not collide unless all of the following are true: the
accesses are to the same 32-bit word polarity (address bits 2 match), the
same 4K byte subbank (address bits 13 and 12 match), the same 16K byte
half bank (address bits 16 match), and the same bank (address bits 21 and
20 match). When an address collision is detected, access is nominally
granted first to the DAGs, then to the store buffer, and finally to the
DMA and cache fill/victim traffic. To ensure adequate DMA bandwidth,
DMA is given highest priority if it has been blocked for more than 16
sequential core clock cycles, or if a second DMA I/O is queued before the
first DMA I/O is processed.
Figure 6-10
shows the L1 Data Memory architecture. In the figure, dotted
lines indicate features that exist only on some Blackfin processors. Please
refer to the hardware reference manual for your particular processor for
more details. While on some processors the EAB and DCB buses shown in
Figure 6-10
connect directly to EBIU and DMA controllers, on deriva-
tives that feature multiple cores or on-chip L2 memories they have to cross
additional arbitration units. Also, these buses are wider than 16 bits on
some parts. For details, refer to the specific Blackfin Processor Hardware
Reference manual for your derivative.
Содержание ADSP-BF53x Blackfin
Страница 38: ...Conventions xxxviii ADSP BF53x BF56x Blackfin Processor Programming Reference...
Страница 134: ...System Reset and Powerup 3 18 ADSP BF53x BF56x Blackfin Processor Programming Reference...
Страница 324: ...Instruction Overview 7 20 ADSP BF53x BF56x Blackfin Processor Programming Reference...
Страница 486: ...Instruction Overview 13 28 ADSP BF53x BF56x Blackfin Processor Programming Reference...
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Страница 742: ...Instruction Overview 19 54 ADSP BF53x BF56x Blackfin Processor Programming Reference...
Страница 752: ...Examples 20 10 ADSP BF53x BF56x Blackfin Processor Programming Reference...
Страница 780: ...Product Identification Register 21 28 ADSP BF53x BF56x Blackfin Processor Programming Reference...
Страница 790: ...ADSP BF535 Flags A 10 ADSP BF53x BF56x Blackfin Processor Programming Reference...
Страница 800: ...Performance Monitor Registers B 10 ADSP BF53x BF56x Blackfin Processor Programming Reference...
Страница 994: ...Instructions Listed By Operation Code C 194 ADSP BF53x BF56x Blackfin Processor Programming Reference...
Страница 1042: ...Index I 40 ADSP BF53x BF56x Blackfin Processor Programming Reference...