Comtech EF Data SDM-2020 - Manual (Page 137)

8–1
Chapter 8. LOW VOLTAGE
DIFFERENTIAL (LVDS)
INTERFACE
This section describes the plug-in LVDS Data Interface used with the SDM-2020
Demodulator.
8.1 Low Voltage Differential Signal (LVDS) Interface (PL/5814)
The section describes the LVDS interface (SP/5814). This plug-in module provides the
physical and electrical interface between an SDM-2020 modulator or demodulator and
DVB or DBS signal sources operating with LVDS electrical characteristics. In TM1449,
this interface is called, “SPI.”
The LVDS interface is compliant with the Digital Video Broadcast synchronous parallel
interface (DVB-SPI) standard. The interface has two 25-pin female D connectors, one for
transmit data and the other for receive data. The data and clock are an 8 bit parallel word
along with a byte clock for DVB operation. There is also a non-DVB serial mode of
operation using the byte clock lines as a serial bit clock and the MSB (Data 7) as serial
data. A separate auxiliary connector provides fault status.
8.1.1 Applicable Documents
Applicable specifications, as referenced herein, include:
EN 80053-9 Interfaces for CATV/SMATV Headends and Similar Professional Equipment.
TIA/EIA-644 Telecommunications Industry Standard, Electrical Characteristics Of Low Voltage
Differential Signaling (LVDS) Interface Circuits (originally Standards Proposal
SP-3357)