Modem Control Circuit Design And Realization

To design and implement the monitoring circuit of modem system, the microcontroller controls all kinds of operations of the modem when receiving the command coming from master controller and sends some parameters from the modem to master controller.ATmega128 microcontroller communicates with master controller via USART; it communicates with DSP chip TMS320C5410A via SPl to supply dynamic reconfiguration information of FPGA and read doppler frequency and SNR that have been estimated by the modem in time; it configures the DDS device AD9851 via general digital I/O ports to switch the main working clock of FPGA; it also exchanges data with FPGA in the way of accessing external SRAM to cutover the transaction. After the hardware designing and software programming, the debugger in system shows that this designed monitoring circuit of the modem accords with the requirements.