ADSP-BF537 Blackfin Processor Hardware Reference
6-19
External Bus Interface Unit
programmed while the AMC is in use. The
EBIU_AMGCTL
register should be
the last control register written to when configuring the processor to
access external memory-mapped asynchronous devices.
Additional information for the
EBIU_AMGCTL
register bits includes:
•
Asynchronous memory clock enable
(
AMCKEN
)
For external devices that need a clock,
CLKOUT
can be enabled by
setting the
AMCKEN
bit in the
EBIU_AMGCTL
register. In systems that
do not use
CLKOUT
, set the
AMCKEN
bit to 0.
•
Asynchronous memory bank enable
(
AMBEN
).
If a bus operation accesses a disabled asynchronous memory bank,
the EBIU responds by acknowledging the transfer and asserting the
error signal on the requesting bus. The error signal propagates back
to the requesting bus master. This generates a hardware exception
to the core, if it is the requester. For DMA mastered requests, the
error is captured in the respective status register. If a bank is not
fully populated with memory, then the memory likely aliases into
multiple address regions within the bank. This aliasing condition is
not detected by the EBIU, and no error response is asserted.
•
Core/DMA priority
(
CDPRIO
).
This bit configures the AMC to control the priority over requests
that occur simultaneously to the EBIU from either processor core
or the DMA controller. When this bit is set to 0, a request from the
core has priority over a request from the DMA controller to the
AMC, unless the DMA is urgent. When the
CDPRIO
bit is set, all
requests from the DMA controller, including the memory DMAs,
have priority over core accesses. For the purposes of this discussion,
core accesses include both data fetches and instruction fetches.
L
The
CDPRIO
bit also applies to the SDC.
Summary of Contents for Blackfin ADSP-BF537
Page 42: ...Contents xlii ADSP BF537 Blackfin Processor Hardware Reference ...
Page 90: ...Development Tools 1 32 ADSP BF537 Blackfin Processor Hardware Reference ...
Page 138: ...Programming Examples 4 26 ADSP BF537 Blackfin Processor Hardware Reference ...
Page 340: ...SDC Programming Examples 6 84 ADSP BF537 Blackfin Processor Hardware Reference ...
Page 606: ...Programming Examples 9 94 ADSP BF537 Blackfin Processor Hardware Reference ...
Page 660: ...Programming Examples 10 54 ADSP BF537 Blackfin Processor Hardware Reference ...
Page 720: ...Electrical Specifications 11 60 ADSP BF537 Blackfin Processor Hardware Reference ...
Page 840: ...Programming Examples 13 42 ADSP BF537 Blackfin Processor Hardware Reference ...
Page 876: ...Programming Examples 14 36 ADSP BF537 Blackfin Processor Hardware Reference ...
Page 938: ...Programming Examples 15 62 ADSP BF537 Blackfin Processor Hardware Reference ...
Page 958: ...Programming Examples 17 12 ADSP BF537 Blackfin Processor Hardware Reference ...
Page 986: ...Programming Examples 18 28 ADSP BF537 Blackfin Processor Hardware Reference ...
Page 1162: ...G 26 ADSP BF537 Blackfin Processor Hardware Reference ...
Page 1218: ...Index I 56 ADSP BF537 Blackfin Processor Hardware Reference ...