HI, AFE5818 engineers:
In my own AFE5818 hardware system, the AFE5818 samples at a rate of 12-bit and 80MHz. In Test Pattern Mode, no matter what data I set the AFE to send, the FPGA can receive the correct data, Which shows that there is no problem with the LVDS transmission circuit and my FPGA firmware. But when I use the normal mode to receive data, error occurred:
1.When channel 1 is connected to GND, the digital output of AFE should be close to 0, but the data jumps between 0 and 4096 , As shown in the figure_1, when I execute the code if “AFE_data[i]> 2048: AFE_data[i] = 4096-AFE_data[i]”, this code indicates that if the data is less than 2048, it will not change, if it is greater than 2048, then the new number is equal to 4096 minus itself, after executing the code, the result seems reasonable. Figure 1 is the original data, and Figure 2 is the data after the code is executed.
2.When channel 1 inputs 40mV, 5MHz sine wave, the original data has the same problem as Figure 1. When f AFE_data[i]> 2048: AFE_data[i] = 4096-AFE_data[i] code is executed, the waveform appears to be drawn Becomes reasonable (Figure 3), the frequency in Figure 3 is 10MHz, twice the input frequency.
