Dbs Mode Receive Sync Pulse Timing; Figure A-13. Dbs Mode Receive Sync Pulse Timing; Figure A-14. Dbs Mode Receive With Extended Sync; Table A-3. Receive Baseband Interface Timing - Comtech EF Data SDM-9000 Installation And Operation Manual

SDM-9000 Satellite Modem
Parameters for TX baseband interface timing are presented in Table A-3.
Parameter
A.2.4.2.1 DBS Mode Receive SYNC Pulse Timing
In DBS mode, a one clock-period-wide sync pulse is supplied coincident with the first bit
of the sync byte (0x47). After the sync byte interval, 187 bytes (1,496 bits) of packet
data, followed by 16 bytes (128 bits) of zeros, are output from the modem. Refer to
Figure A-13.
Receive packets that could not be corrected by the Reed-Solomon decoder are indicated
with an extended sync pulse (two clock-periods-wide) as shown in Figure A-14.
Rev. 4

Table A-3. Receive Baseband Interface Timing

t Delay time, CLOCK to DATA or SYNC valid
cko
t Hold time, CLOCK to DATA or SYNC invalid
h
t CLOCK low time
cl
t CLOCK high time
ch

Figure A-13. DBS Mode Receive SYNC Pulse Timing

Figure A-14. DBS Mode Receive with Extended SYNC

Description
Options
Min Max
5 ns
2 ns
8 ns
8 ns
A–17