ADSP-BF535 Blackfin Processor Hardware Reference
6-15
Memory
The ADSP-BF535 core reads the 16 KB instruction memory through the
64-bit wide instruction fetch bus. All addresses from this bus are 64-bit
aligned. Each instruction fetch can return any combination of 16-, 32- or
64-bit instructions (for example, four 16-bit instructions, two 16-bit
instructions and one 32-bit instruction, or one 64-bit instruction).
The DAGs, which are described in Chapter 5, cannot access L1 Instruc-
tion Memory directly. If instruction space must be accessed as data, L2
memory must be used, because it serves as a unified space for both instruc-
tions and data. A DAG reference to instruction memory SRAM space
generates an exception (see
“Exceptions” on page 4-38
).
Write access to the L1 instruction SRAM memory must be made through
the 64-bit wide system DMA port. Because the SRAM is implemented as
four single ported sub-banks, the instruction memory is effectively dual
ported. Provided that system and core accesses do not collide on the same
sub-bank, effective dual porting of the instruction memory is achieved. If
both system and core attempt to access the same bank, the system DMA
controller has priority over the core instruction fetch.
Alternatively, both the
IMC
and
ENIM
bits in the
IMEM_CONTROL
register can
disable these sub-banks entirely. The configuration state in the control
register can be modified only while in Supervisor mode or Emulation
mode.
Before changing the configuration state, be sure to flush the cache
or move all modified data from the SRAM, if so configured.
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...