ADSP-214xx SHARC Processor Hardware Reference
10-33
Serial Ports
Multichannel mode operates completely independently and each
uses its own
SCLK
and
FS
signal programmed using the SRU. The
FS
signal synchronizes the channels and restarts each multichannel
sequence. The
SPORTx_FS
signal initiates the start of the channel 0
data word. The
FS
period in multichannel is defined as:
FS
period =
SLEN
× number of channels. The frame sync can be
configured in master or slave mode based on the setting of the
IMFS
bit and the logic level can be changed using the
LMFS
bit. The edge
can be changed if bit 2 (
FSED
) is set in the
SPCTLNx
register.
Frame Sync Delay (MFD)
The 4-bit
MFD
field (bits 4–1) in the multichannel control registers
(
SPMCTLx
) specifies a delay between the frame sync pulse and the first data
bit in multichannel mode. The value of
MFD
is the number of serial clock
cycles of the delay. Multichannel frame delay allows the processor to work
with different types of telephony interface devices.
A value of zero for
MFD
causes the frame sync to be concurrent with the
first data bit. The maximum value allowed for
MFD
is 15. A new frame sync
may occur before data from the last frame has been received, because
blocks of data occur back to back.
Transmit Data Valid Signal
Each SPORT has its own transmit data valid signal (
SPORTx_TDV_0
) which
is active during the transmission of an enabled word. Because the serial
port’s receiver signals are three-stated when the time slot is not active, the
SPORTx_TDV_0
signal specifies if the SPORT data is being driven by the
processor.
After the
TXSPxA
transmit buffer is loaded, transmission begins and the
SPORTx_TDV
signal is asserted.
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...