taxi/rtl/lss/taxi_uart.sv

// SPDX-License-Identifier: CERN-OHL-S-2.0
/*

Copyright (c) 2014-2025 FPGA Ninja, LLC

Authors:
- Alex Forencich

*/

`resetall
`timescale 1ns / 1ps
`default_nettype none

/*
 * AXI4-Stream UART
 */
module taxi_uart #(
    parameter PRE_W = 16
)
(
    input  wire logic              clk,
    input  wire logic              rst,

    /*
     * AXI4-Stream input (sink)
     */
    taxi_axis_if.snk               s_axis_tx,

    /*
     * AXI4-Stream output (source)
     */
    taxi_axis_if.src               m_axis_rx,

    /*
     * UART interface
     */
    input  wire logic              rxd,
    output wire logic              txd,

    /*
     * Status
     */
    output wire logic              tx_busy,
    output wire logic              rx_busy,
    output wire logic              rx_overrun_error,
    output wire logic              rx_frame_error,

    /*
     * Configuration
     */
    input  wire logic [PRE_W-1:0]  prescale

);

wire baud_clk;

taxi_uart_brg #(
    .PRE_W(PRE_W)
)
uart_brg_inst (
    .clk(clk),
    .rst(rst),

    /*
     * Baud rate pulse out
     */
    .baud_clk(baud_clk),

    /*
     * Configuration
     */
    .prescale(prescale)
);

taxi_uart_tx
uart_tx_inst (
    .clk(clk),
    .rst(rst),

    /*
     * AXI4-Stream input (sink)
     */
    .s_axis_tx(s_axis_tx),

    /*
     * UART interface
     */
    .txd(txd),

    /*
     * Status
     */
    .busy(tx_busy),

    /*
     * Baud rate pulse in
     */
    .baud_clk(baud_clk)
);

taxi_uart_rx
uart_rx_inst (
    .clk(clk),
    .rst(rst),

    /*
     * AXI4-Stream output (source)
     */
    .m_axis_rx(m_axis_rx),

    /*
     * UART interface
     */
    .rxd(rxd),

    /*
     * Status
     */
    .busy(rx_busy),
    .overrun_error(rx_overrun_error),
    .frame_error(rx_frame_error),

    /*
     * Baud rate pulse in
     */
    .baud_clk(baud_clk)
);

endmodule

`resetall