FPGA UART Bubble Sort

In this project, we implemented a simple UART protocol on the AX309 Xilinx Spartan-6 FPGA. The goal was to send a sequence of numbers to the FPGA using this UART protocol. Upon reception, the FPGA employs a Bubble Sort algorithm to sort the numbers, returning the sorted array to the connected PC. The development environment used for programming the FPGA was Xilinx ISE.

Code Overview

1. Bubble Sort Algorithm (bubblesort.vhdl):

   • VHDL implementation of the Bubble Sort algorithm designed for sorting an array of numbers.
   • Input:
     • Clock signal (clk)
     • Reset signal (reset)
     • Input array (in_array)
   • Output:
     • Sorted array (sorted_array)
   • The sorting process is triggered by the rising edge of the clock signal.

2. UART Implementation (uart.vhdl):

   • VHDL code implementing a UART module with generic parameters for divisor configuration.
   • Input:
     • Clock signal (clk)
     • Reset signal (reset)
     • Transmit data (txdata)
     • Write signal (wr)
     • Read signal (rd)
   • Output:
     • Received data (rxdata)
     • Flags for transmission availability (tx_avail), transmission busy (tx_busy), received data availability (rx_avail), received data full (rx_full), and reception error (rx_error).
   • The UART module is designed to handle both transmitting and receiving data.

3. UART Receiver (uart_rx.vhdl):

   • VHDL code for the UART receiver, which includes synchronization logic and error checking.
   • Input:
     • Clock signal (clk)
     • Reset signal (reset)
     • Input data (rxd)
     • Clear signal (clear)
   • Output:
     • Received data (dout)
     • Flags for data availability (avail) and error (error).

4. UART Transmitter (uart_tx.vhdl):

   • VHDL code for the UART transmitter, which handles data transmission with start and stop bits.
   • Input:
     • Clock signal (clk)
     • Reset signal (reset)
     • Transmit data (din)
     • Write signal (wr)
   • Output:
     • Transmission busy flag (busy)
     • Transmit data line (txd).

How to Use

1. Program the FPGA using Xilinx ISE with the provided VHDL files.
2. Connect the FPGA to a PC through the UART interface.
3. Send a sequence of numbers from the PC to the FPGA using the implemented UART protocol.
4. Receive the sorted array back from the FPGA.