ADSP-214xx SHARC Processor Hardware Reference
15-27
Serial Peripheral Interface Ports
2. The
SPIEN
control bit in
SPICTL
is cleared, disabling the SPI
system.
3. The
MME
status bit in
SPISTAT
is set.
4. An SPI interrupt is generated.
These four conditions persist until the
MME
bit is cleared by a write
1-to-clear (W1C-type) software operation. Until the
MME
bit is cleared, the
SPI cannot be re-enabled, even as a slave. Hardware prevents the program
from setting either
SPIEN
or
SPIMS
while
MME
is set.
When
MME
is cleared, the interrupt is deactivated. Before attempting to
re-enable the SPI as a master, the state of the
SPI_DS_I
input pin should
be checked to ensure that it is high; otherwise, once
SPIEN
and
SPIMS
are
set, another mode-fault error condition will immediately occur. The state
of the input pin is reflected in the input slave select status bit (bit 7) in the
SPIFLG
register.
As a result of
SPIEN
and
SPIMS
being cleared, the SPI data and clock pin
drivers (
MOSI
,
MISO
, and
SPICLK
) are disabled. However, the slave-select
output pins revert to control by the processor flag I/O module registers.
This may cause contention on the slave-select lines if these lines are still
being driven by the processor.
Debug Features
The following sections provide information on features that help in
debugging SPI software.
Shadow Receive Buffers
A pair of read-only (RO) shadow registers for the receive data buffers,
RXSPI
and
RXSPIB
are available for use in debugging software. These regis-
ters,
RXSPI_SHADOW
and
RXSPIB_SHADOW
, are located at different addresses
www.BDTIC.com/ADI
Содержание SHARC ADSP-214 Series
Страница 60: ...Contents lx ADSP 214xx SHARC Processor Hardware Reference www BDTIC com ADI...
Страница 72: ...Notation Conventions lxxii ADSP 214xx SHARC Processor Hardware Reference www BDTIC com ADI...
Страница 130: ...Programming Model 2 52 ADSP 214xx SHARC Processor Hardware Reference www BDTIC com ADI...
Страница 264: ...Programming Models 3 134 ADSP 214xx SHARC Processor Hardware Reference www BDTIC com ADI...
Страница 290: ...Programming Model 4 26 ADSP 214xx SHARC Processor Hardware Reference www BDTIC com ADI...
Страница 296: ...Programming Model 5 6 ADSP 214xx SHARC Processor Hardware Reference www BDTIC com ADI...
Страница 396: ...Effect Latency 7 28 ADSP 214xx SHARC Processor Hardware Reference www BDTIC com ADI...
Страница 520: ...Programming Model 10 62 ADSP 214xx SHARC Processor Hardware Reference www BDTIC com ADI...
Страница 616: ...Debug Features 14 22 ADSP 214xx SHARC Processor Hardware Reference www BDTIC com ADI...
Страница 656: ...Programming Model 15 40 ADSP 214xx SHARC Processor Hardware Reference www BDTIC com ADI...
Страница 714: ...Programming Model 19 10 ADSP 214xx SHARC Processor Hardware Reference www BDTIC com ADI...
Страница 1132: ...Register Listing A 306 ADSP 214xx SHARC Processor Hardware Reference www BDTIC com ADI...
Страница 1192: ...Index I 34 ADSP 214xx SHARC Processor Hardware Reference www BDTIC com ADI...