Comtech EF Data SDM-2020, Installation And Operation Manual

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SDM-2020 Satellite Demodulator Data Interfaces
Rev.3 A–37
Table A-19. Transmit Timing Parameters
Parameter Description Min Max Units
f Operating frequency (1/T) 1.5 100 MHz
T Clock period (1/f) 10 666 nsec
t
w
Clock pulse width 4 - nsec
t
su
Setup time, DATA or SYNC to CLOCK 3 - nsec
t
h
Hold time, CLOCK to DATA or SYNC invalid 3 - Nsec
The timing parameters for the serial data receive interface are listed in Table A-20.
Table A-20. Receive Timing Parameters
Parameter Description Min Max Units
f Operating frequency (1/T) 1.5 100 MHz
T Clock period (T) 10 666 nsec
t
w
Clock pulse width 4 - nsec
t
su
Setup time, DATA, DVALID, or SYNC to
CLOCK 3 - nsec
t
h
Hold time, CLOCK to DATA, DVALID or
SYNC invalid 3 - nsec
A.5.4.7 Terrestrial TX Clock Phase
The ECL/HSSI interface supports TX clock phase inversion. Terrestrial data is sampled
on the falling edge of TT clock in normal phase selection. In inverted phase selection, the
terrestrial data will be sampled on the rising edge of TT clock.
A.5.4.8 Terrestrial RX Clock Phase
The ECL/HSSI interface supports RX clock phase inversion. Terrestrial data (RD) is
synchronous to RT. In normal mode, the falling edge of the RT clock will be centered on
the RD signal. In inverted phase selection, the rising edge of RT clock will be centered on
the RD signal.