Comtech EF Data SDM-2020 - Manual (Page 158)

SDM-2020 Satellite Demodulator Revision 4
ECL/HSSI Data Interface MN/SDM2020D.IOM
10–6
0 1 0 0 1 0 1 1
8 Bits Sync 1496 Bits Payload
SYNC
DATA
DVALID
CLOCK
0 1 0 0 1 0 1 1
8 Bits Sync 128 Bits RS
Figure 10-4. 204 Byte DBS Serial Format
10.1.4.2 Terrestrial Signal Definition
HSSI (High Speed Serial Interface per Cisco Systems, Inc.) and EIA-613 (High Speed
Serial Interface for Data Terminal Equipment and Data Circuit-Terminating Equipment)
specifications define the high-speed serial port functionality. The serial port is referred to
as the HSSI Interface. The HSSI Interface is compatible with EIA-613/EIA-612.
Additional non-standard signals will be included on reserved pins and are highlighted in
the signal definition table.
Note: Standard EIA-613 defines the interconnection of data terminal equipment (DTE)
and data circuit-termination equipment (DCE) utilizing high speed serial circuits. The
SDM-2020 modulator/demodulator is defined as a DCE.
Refer to Table 10-4 for HSSI pinouts and Figure 10-5 for pinout locations.
Figure 10-6 shows the HSSI signal flow and naming convention for defined signals.