design and implementation of a format conversion system on the Altera NIOS board(QUARTUS) which reads an analogue input, converts it into digital data, and then does the reverse conversion back into analogue format. This will be done by taking an analogue an analogue input using SPI MCP3202 12-Bit A/D converter to generate the digital data stream and then the digital data will be used to generate an analogue output using Analog Devices 8-bit SPI AD7303 D/A converter.