Data Transfers
15-18
ADSP-214xx SHARC Processor Hardware Reference
When word to word delay is enabled (
WTWDEN
= 1) in the
SPICTL
register,
then T3 may vary with respect to the value programmed using the
STDC
bits in the
SPIBAUD
register. So the word to word delay T4 is:
This is shown as:
T4 = 1.5 SPI clock T3 and
T3 = 1.5 SPI clock period for
STDC
= 0,
BAUDR
= 1, RX master
T3 = 0.5 SPI clock period for
STDC
= 0, in all other cases.
T3 =
STDC
× SPI clock period for
STDC
> 0.
Data Transfers
The SPI is capable of transferring data via the core and DMA. The follow-
ing sections describe these transfer types.
Buffers
The SPI allows 3 different word lengths, which impacts the transmit or
receive buffers with different packing methods.
8-bit word.
The SPI port sends out only the lower eight bits of the word
written to the SPI buffer. For example, when receiving, the SPI port packs
the 8-bit word to the lower 32 bits of the
RXSPI
buffer while the upper bits
Figure 15-7. SPICLK Timing
SPI_CLK_I
CPHASE=0
T1
T2
T3
T4
SPI_DS_I
TO SLAVE
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Содержание SHARC ADSP-214 Series
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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...