Design of a UART –to- Bell202 converter SoC by using Altera-Intel FPGA

The widespread use of Field Programmable Gate Array (FPGA) in the consumer electronics market makes designers integrate more and more solutions with these programmable logic devices. In this paper, the authors use a CYCLONE V 5CSEMA5FC31C6N Altera-Intel FPGA in order to implement a UART-to-Bell202 converter for the direct interfacing of an FPGA with an analogue line on the voice band, not still available for industrial and consumer electronic for communications applications. In particular, a transmitter is created with an Audio Shift Keying modulation without phase continuity, capable of converting UART signals coming from any UART transmitter (for example a personal computer, PC) into a modulated signal. The design has been performed using the Terasic DE1-SoC development board, while instrumental tests have been performed with a ZEROPLUS LAP-C logic states analyzer and a CML1102 oscilloscope..