I have a DE0-nano FPGA board and I am trying to establish a serial connection with my PC.
I am using the RS232 implementation from here: http://www.fpga4fun.com/SerialInterface.html
I have tested sending from the FPGA, and it worked perfectly. However, when I try to send to the FPGA, it seems to not be working.
Here is my verilog code:
module Learning( input clk, input RxD, output LED ); wire RxD_data_ready; wire [7:0] RxD_data; reg [7:0] data; async_receiver RX(.clk(clk), .RxD(RxD), .RxD_data_ready(RxD_data_ready), .RxD_data(RxD_data)); always @(posedge clk) if(RxD_data_ready) data <= RxD_data; assign LED = (data == 8'h24); endmodule
Basically I have designed it such that a specific LED on my board turns on while I am sending the hexadecimal value 24. Since I am sending this value at a very high frequency I do expect the LED to remain on for the whole transmission. However, nothing is happening. It stays off.
I already tried the reverse bit option from my rs232 program. Also, using a symmetrical value like 0x55 didn't work.
What could be the issue?