ADSP-214xx SHARC Processor Hardware Reference
9-11
Digital Application/Digital Peripheral Interfaces
Pin Buffers as Open Drain
For peripherals like the TWI and SPI (multi processing), the bus protocol
requires the pin drivers to work in open drain mode (
) for trans-
mit and receive operation. The signal input of the assigned pin buffer is
tied low. The peripheral's data output signal is connected to the
PBEN
sig-
nal. In open drain mode, if
PBEN
= low, the level on the pin is depending
on the bus activities. If
PBEN
= high, the driver is conducting (input always
low level) and ties the bus low level. Note that for the SPI the
ODP
bit in
the
SPICTL
register must be enabled.
In open drain mode the data output signal is the peripheral’s
PBEN_O
signal
DAI/DPI Pin Buffer Status
The signal levels on the DAI/DPI pins can be read with the
DAI
/
DPI_PIN_STAT
registers. This allows conditions like for example:
Figure 9-6. Pin Buffer as Open Drain
IN
OUT
PIN
ENABLE
DAI_PBxx_I
DAI_PBxx_O
PBENxx_I
EXTERNAL DAI
PIN BUFFER
INTERFACE
TO SRU
PIN
BUFFER
PIN BUFFER
OUTPUT
PIN BUFFER
INPUT
(TIED LOW)
PIN BUFFER
ENABLE
TWI_DATA_PBEN_O
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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...