ADC (Analog to Digital Converter) Module for FPGA Design | Your Electronics Open Source

Description

The Digilent Inc. from USA is a vendor for FPGA solutions. The portfolio of the company includes high quality educational FPGA boards and adequate peripheral modules as ADCs and DACs.
This is equipped with the National Semiconductor’s ADCS7476MSPS 12-bit A/D converter providing up to 1 MSample/second on two independent channels. The analog input is conditioned by the 2 pole Sallen-Key anti-alias filter. Due to its small size (0.95" x 0.80") and the 6-pin standard header it becomes suitable not only for didactic use, but for some commercial applications also.
And now let’s focus on the FPGA interface. By opening the ADC datasheet, you will find out that it has a standards SPI interface. Trough this you can introduce the samples for the further processing in the FPGA design.
Some designers can get lucky and they already have some Intellectual Property for the SPI interface. They don’t have anything to do just to instantiate this module in their design and the interfacing is done. But some of the designers are not so lucky. They have to prepare themselves the ADC interface for DMA controller or other industry standard bus.
My advice is to build an interface heaving the structure Form Fig. 1. This structure contains a buffer; on the write side there is a state machine reading the samples and writing them to the buffer; on the read side another state machine reads the samples and passes towards the interface.

Original URL

http://dev.emcelettronica.com/adc-analog-digital-converter-module-fpga-design

http://dev.emcelettronica.com/adc-analog-digital-converter-module-fpga-design