Add sample image processing module to Spartan 6 demo project

fpga/xilinx/digilent/spartan_6/s6_remotefpga_test/main.v

@@ -105,13 +105,19 @@ module main(
 	//
 	//-------------------------------------------------------------------------------------------------------
 
-	reg sram_wren_in = 0;
+	wire sram_wren_in;
 	wire sram_clock_in;
-	reg [7:0] sram_data_in = 0;
-	reg [13:0] sram_address_in = 0;
-	wire [7:0] sram_data_out = 0;
+	wire [7:0] sram_data_in;
+	wire [13:0] sram_address_in;
+	wire [7:0] sram_data_out;
 	wire sram_available;
-	reg sram_processing_done = 1;
+	wire sram_processing_done;
+
+	// Uncomment this block if no image processing module is provided
+	// assign sram_wren_in = 0;
+	// assign sram_data_in = 0;
+	// assign sram_address_in = 0;
+	// assign sram_processing_done = 1;
 	
 	assign sram_clock_in = main_fifty_clock;
 
@@ -149,6 +155,17 @@ module main(
 		.sixteen_bit_output(sixteen_bit_output), .lcd_data_in_address(lcd_data_in_address),
 		.lcd_data_in_data(lcd_data_in_data), .lcd_data_in_enable(lcd_data_in_enable));
 
+	//-------------------------------------------------------------------------------------------------------
+	//
+	// User Image Processing Module Instantiation
+	//
+	// Instantiate the simple userimage processing module to invert the bits in any images sent to the FPGA
+	//
+	//-------------------------------------------------------------------------------------------------------
+
+	sample_image_processing_demo sample_image_processing_demo(.clk(clk_div_by_two), .wren(sram_wren_in), .dout(sram_data_in), .addr(sram_address_in),
+		.din(sram_data_out), .enable(sram_available), .done(sram_processing_done));
+
 endmodule
 
 //-------------------------------------------------------------------------------------------------------
@@ -202,3 +219,53 @@ module sample_demo(clk, four_bit_input, four_bit_output, eight_bit_input, eight_
 		end
 	end
 endmodule
+
+//-------------------------------------------------------------------------------------------------------
+//
+// Demo User Image Processing Module
+//
+//-------------------------------------------------------------------------------------------------------
+
+module sample_image_processing_demo(clk, wren, dout, addr, din, enable, done);
+	input clk;
+
+	output reg wren;
+	output reg [7:0] dout;
+	output reg [13:0] addr;
+	input [7:0] din;
+	input enable;
+	output reg done;
+
+	reg prev_enable;
+	reg [13:0] counter;
+	reg toggler;
+
+	always @(posedge clk) begin
+		if ((enable == 1) && (prev_enable == 0)) begin
+			counter = 0;
+			toggler = 0;
+		end
+		if ((enable == 1) && (done == 0)) begin
+			if (toggler == 0) begin
+				wren = 0;
+				addr = counter;
+				toggler = 1;
+			end else begin
+				dout = ~din;
+				wren = 1;
+				addr = counter;
+				counter = counter + 1;
+				if (counter >= 16383) begin
+					done = 1;
+				end
+				toggler = 0;
+			end
+		end
+		if (enable == 0) begin
+			done = 0;
+			addr = 0;
+			toggler = 0;
+		end
+		prev_enable = enable;
+	end
+endmodule