SYNCHRONOUS SERIAL INTERFACE (SSI)
MOTOROLA
PORT C
6 - 157
6.4.9
Example Circuits
The DSP-to-DSP serial network shown in Figure 6-91 uses no additional logic chips for the
network connection. All serial data is synchronized to the data source (all serial clocks and
serial syncs are common). This basic configuration is useful for decimation and data reduc-
tion when more processing power is needed than one DSP can provide. Cascading DSPs
in this manner is useful in several network topologies including star and ring networks.
RECEIVE CLOCK
RECEIVE DATA
B7
B6
B5
B4
B3
B2
B1
B0
7
6
5
4
3
2
1
0
RDF
TDE
ROE
TUE
RFS
TFS
IF1
IF0
X:$FFEE
SSI STATUS REGISTER (SSISR)
(READ)
INPUT FLAGS
SAMPLE
INPUT FLAG
Figure 6-90 Input Flags
DATA
IN
DSP56002
SRD
STD
SCK
SC2
SERIAL CLOCK
SERIAL SYNC
DSP56002
SRD
STD
SCK
SC2
DSP56002
SRD
STD
SCK
SC2
DSP56002
SRD
STD
SCK
SC2
DATA
OUT
Figure 6-91 SSI Cascaded Multi-DSP System
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Freescale Semiconductor, Inc.
For More Information On This Product,
Go to: www.freescale.com
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