Operating Modes
15-16
ADSP-214xx SHARC Processor Hardware Reference
asserted (active-low) between transfers or be deasserted between transfers.
This is controlled in software using the
SPIFLGx
bits (
SPIFLG
register). For
example, to configure
SPI_FLG1_O
as a slave-select, set
DS1EN
= 1 and
SPIFLG1
= 1. As soon as this
SPIFLG
register write takes effect, the
SPI_FLG1_O
(slave-select output pin) becomes active (Low).
If needed,
SPI_FLGx_O
can be cycled high and low between transfers by
setting the
SPIFLG[x]
bit to 1 and back to 0. Otherwise,
SPI_FLGx_O
remains active between transfers.
If
CPHASE
= 0 or
CHPASE
= 1 and
AUTOSDS
= 1, all selected outputs are
asserted only for the duration of the transfer. This is controlled by the
internal SPI hardware. In this case, the
SPIFLGx
bits are ignored. For
example, to configure
SPI_FLG1_O
as a slave-select, it is only necessary to
set
DS1EN
=1.
Note that the
SPI_FLGx_O
signals behave as slave-select outputs only if the
SPI module is enabled as a master. Otherwise, none of the bits in the
SPIFLG
register have any effect.
Figure 15-6. SPI Transfer Protocol for CPHASE = 1
1
2
3
4
5
6
7
8
*
6
6
5
4
3
5
4
3
2
1
LSB
*
2
1
LSB
MSB
MSB
* = UNDEFINED
*
CLOCK CYCLE#
SPI_CLK_O
CLKPL=0
(SPI MODE 1)
SPI_CLK_O
CLKPL=1
(SPI MODE 3)
SPI_MOSI_O
FROM MASTER
SPI_MISO_O
FROM SLAVE
SPI_DS_I
TO MASTER
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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...