gw1n FPGA reads ADS8598H actual DC measurement

littleshrimp

gw1n FPGA reads ADS8598H actual DC measurement [Copy link]

 

The experimental board has not been fully soldered yet. Use flying wires to connect to the FPGA to measure its 3.3V power supply. The multimeter measures 3.293V.

At present, the FPGA side directly checks the data through the logic analyzer and measures the data of channel 1 and channel 8. Now the data is normal, but it may be related to the flying line. Oversampling is not turned on, and the data fluctuates greatly.

Select a set of data and use EXCEL to calculate the voltage.

Thanks to the fast compilation of Gaoyun software, the debugging process can be downloaded and tested repeatedly, saving the simulation.

At first I wanted to use Serial Data Read, but after reading the data sheet carefully during debugging, I found that the 8-channel sampling rate could not achieve the maximum sampling rate of 500KSPS.

Regarding serial data reading, according to the manual, if oversampling is not used, the data can be read during the conversion period, and a sampling rate of 500K can be achieved through DOUTA and DOUTB. However, data can only be read during the busy rising edge during the conversion period. When there is no oversampling, the busy high level time is 1.24us, and the minimum width of tsclk is 50ns. In this way, the maximum number of tsclk cycles during a busy high level period is 24.8. The two data of douta and doutb can only output 2 groups of 18-bit data at most. I don't quite understand this.

Finally, it was changed to Byte Mode, so that there are only 8 data lines and a few less lines can be compressed.

Jacktang

The equipment is quite complete, including logic analyzer

littleshrimp

Jacktang posted on 2022-1-19 07:17 The equipment is quite complete, including logic analyzers

FPGA's built-in logic analyzer