Comtech EF Data DMD1050TS - Baseband Processing Printed Circuit Card; Figure 3-3. DMD1050 TS Baseband Processing Card Block Diagram

DMD1050TS Satellite Modem Board
Revision 1
Theory of Operation 3–3 MN-DMD1050TS
3.1.2 Baseband Processing Printed Circuit Card
The advent of million-plus gate count Field-programmable Gate Arrays (FPGAs), advanced logic
synthesis tools and Digital Signal Processors (DSPs) providing hundreds of Microprocessor
without Interlocked Pipeline Stages (MIPs) supported the design of a software-configurable
modem. Large, fast FPGAs now provide designers with what is essentially an on-the-fly
programmable Application-specific Integrated Circuit (ASIC).
High speed, complex digital logic functions that previously could only be implemented in
dedicated integrated circuits, are now downloaded from a micro-controller through a serial or
peripheral interface. When a new digital logic function is needed, a new configuration file is
loaded into the FPGA. There is no limit to the number of digital logic configurations available to
the FPGA, aside from the amount of Flash memory available to the system microprocessor for
storage of configuration files.
The DMD1050TS Baseband Processing Printed Circuit Card provides a flexible architecture that
allows many different modes of terrestrial and satellite framing, various Forward Error Correction
(FEC) options, digital voice processing and several different modulation/demodulation formats.
Also included on the Baseband Printed Circuit Card are a MIL-188-114A/RS-422 synchronous
interface and a two-port 10/100 Ethernet Bridge interface.
Figure 3-3. DMD1050TS Baseband Processing Card Block Diagram
Battery
Xtal
uProcessor
PCMCIA
Controller
SCC2
SMC2
SCC3
GPIO
uProc
Bus
SPI
40
MHz
x2
Compact
Flash
Demodulator
FPGA
SDRAM
2 x
Boot
Flash
8 Mbx8
256 Mbx16
25 MHz
Xtal
Ethernet
PHY
Relays
Fault
(DB9)
RLLP
Terminal
Ethernet
DAC
AGC
Modulator
FPGA
SCT/SCTE
Rx SAT
Loopback
80 MHz
uProc Bus
SPI Bus
I/Q
TP
2 x
r2r
Q
I
ADC
ADC
Analog I Filter
Analog I Inv Filter
Analog Q Inv Filter
Analog Q Filter
Alias
Filter
Alias
Filter
Analog I Unfilter
Analog I Inv Unfilter
Analog Q Unfilter
Analog Q Inv Unfilter
DMD1050 IF Board Connector (40-Pin Header)
I
Q
Analog Q Inv Unfilter
Analog Q Unfilter
Analog I Inv Unfilter
Analog I Unfilter
Analog I Filter
Analog I Inv Filter
Analog Q Filter
Analog Q Inv Filter
Alias
Filter
Alias
Filter
ADC
ADC
DB-25 Sync Data (RS-422, MIL-STD-188-114A) & Ethernet 10Base-T
TPC Codec
ADC
Serial
EEPROM
SPI Bus
SPI Bus
Terrestrial Data
LPF
DAC
Tx
Clk
SCT
LPF
R2R
SCT
R2R
LPF
Insert DSP
Mem Space DMA
Drop DSP
Mem Space DMA
Buf
SRAM
40 MHz
40 MHz
Async (DB-9)
Buffers
Terrestrial Data
Buffers
Terrestrial Data
Buffers
10 Mhz
OCXO
PLL
Buffers
Buffers