Data Acquisition via RS-232 and Universal Serial Bus From a Field Programmable Gate Array

摘要

The Field Programmable Gate Array (FPGA) offers a flexible solution for transferring data obtained from hardware to a PC for analysis and storage. Traditionally, an RS-232 serial interface is used to connect hardware to the PC. The RS-232 protocol is straightforward to implement with minimum hardware support. However, the presence of the Universal Serial Bus (USB) protocol has largely replaced traditional RS-232 communications, mainly due to a higher data rate and ease of configuration. In this thesis, models for the FPGA to send data in memory via RS-232 and USB were developed, as well as programs on the PC to accept those data streams. By using timing alone (no bidirectional communication), the RS-232 model could send data up to 36.9 kbps where as the USB model achieved a data rate of 702.6 kbps. By using the TXE pin and writing data only when the chip was ready, a 3.17 Mbps transfer rate was achieved.