ADSP-2126x SHARC Processor Hardware Reference
10-41
Serial Peripheral Interface Port
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
SPIDS
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 flag I/O module registers. This may
cause contention on the slave-select lines if these lines are still being driven
by the ADSP-2126x. In order to ensure that the slave-select output drivers
are disabled once a
MME
error occurs, the program must configure these
pins as inputs by clearing (= 0) the
FLG0O
,
FLG1O
,
FLG2O
, and
FLG3O
bits in
the
FLAGS
register prior to configuring the SPI port. See the
Register (FLAGS)” on page A-39
.
Transmission Error Bit (TUNF)
The
TUNF
bit is set in the
SPISTAT
register when all of the conditions of
transmission are met and there is no new data in
TXSPI
(
TXSPI
is empty).
In this case, the transmission contents depend on the state of the
SENDZ
bit
in the
SPICTL
register. The
TUNF
bit is cleared by a W1C-type software
operation.
Summary of Contents for ADSP-21261 SHARC
Page 30: ...Contents xxx ADSP 2126x SHARC Processor Hardware Reference ...
Page 40: ...Register Diagram Conventions xl ADSP 2126x SHARC Processor Hardware Reference ...
Page 58: ...Differences From Previous SHARCs 1 18 ADSP 2126x SHARC Processor Hardware Reference ...
Page 112: ...Secondary Processing Element PEy 2 54 ADSP 2126x SHARC Processor Hardware Reference ...
Page 178: ...Summary 3 66 ADSP 2126x SHARC Processor Hardware Reference ...
Page 204: ...DAG Instruction Summary 4 26 ADSP 2126x SHARC Processor Hardware Reference ...
Page 322: ...Setting Up DMA 7 32 ADSP 2126x SHARC Processor Hardware Reference ...
Page 436: ...SPORT Programming Examples 9 86 ADSP 2126x SHARC Processor Hardware Reference ...
Page 521: ...ADSP 2126x SHARC Processor Hardware Reference 11 31 Input Data Port rts IDP_ISR end ...
Page 522: ...Input Data Port Programming Example 11 32 ADSP 2126x SHARC Processor Hardware Reference ...
Page 590: ...Timer Programming Examples 14 20 ADSP 2126x SHARC Processor Hardware Reference ...
Page 796: ...I O Processor Registers A 174 ADSP 2126x SHARC Processor Hardware Reference ...
Page 800: ...B 4 ADSP 2126x SHARC Processor Core Manual ...
Page 846: ...Index I 36 ADSP 2126x SHARC Processor Hardware Reference ...