ADSP-21368 SHARC Processor Hardware Reference 5-27
Serial Ports
Although the eight SPORTs are programmable for data direction in the
standard mode of operation, their programmability is restricted for multi-
channel operations. The following points summarize these limitations:
1. The primary A channels of SPORT1, 3, 5, and 7 are capable of
expansion only, and the primary A channels of SPORT0, 2, 4, and
6 are capable of companding only.
2. In previous SHARC processors in multichannel mode, SPORTs
worked in pairs where, for example, SPORT0 was the transmit
channel, and SPORT1 was the receive channel. In the
ADSP-21367/8/9 and ADSP-2137x processors, the SPORTs work
independently.
Since the SPORTs now work independently, clocks are not inter-
nally connected. Programs need to use SRU1 to connect clocks to
two SPORTs separately. For more information, see “Group A
Connections—Clock Signals” on page 4-19.
3. Receive comparison is not supported.
Figure 5-5 shows an example of timing for a multichannel transfer with
SPORT pairing using SPORT0 and 1. The transfer has the following
characteristics:
• The transfer uses the TDM method where serial data is sent or
received on different channels while sharing the same serial bus.
• SPORT1 is configured as the receiver and SPORT1_FS signals the
start of a frame for each multichannel SPORT pairing.
• Unlike previous SHARC processors where the
SPORT0_FS was used
as a transmit data valid signal for external logic and was active only
on transmit channels, in the ADSP-21367/8/9 and ADSP-2137x
processors, SPORT0_FS is not used as a transmit data valid signal.
Each SPORT has a dedicated data valid pin (
SPORTx_TDV) and pro-
grams use SRU1 to connect them to external pins.
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