--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/fpga/sniffer-pps/uart_tx.v	Tue Aug 29 20:05:23 2023 +0000
@@ -0,0 +1,45 @@
+/*
+ * This Verilog module captures the UART output logic.
+ */
+
+module uart_tx (IntClk, Tx_trigger, Tx_data, UART_out);
+
+input IntClk;
+input Tx_trigger;
+input [15:0] Tx_data;
+output UART_out;
+reg UART_out;
+
+reg tx_active;
+reg [1:0] clk_div;
+reg [4:0] bit_count;
+reg [17:0] shift_reg;
+
+initial begin
+	tx_active = 1'b0;
+	UART_out = 1'b1;
+end
+
+always @(posedge IntClk)
+	if (!tx_active && Tx_trigger)
+	    begin
+		tx_active <= 1'b1;
+		UART_out <= 1'b0;
+		clk_div <= 2'd0;
+		shift_reg <= {Tx_data[15:8],2'b01,Tx_data[7:0]};
+		bit_count <= 5'd0;
+	    end
+	else if (tx_active)
+	    begin
+		clk_div <= clk_div + 2'd1;
+		if (clk_div == 2'd3)
+		    begin
+			UART_out <= shift_reg[0];
+			shift_reg <= {1,shift_reg[17:1]};
+			bit_count <= bit_count + 5'd1;
+			if (bit_count == 5'd19)
+				tx_active <= 1'b0;
+		end
+	end
+
+endmodule