Fix image distortion when certain greyscale values are utilized

Store last used values in FPGA viewer and programmer GUI for convenience on GUI restart

2 files changed, 157 insertions, 160 deletions

diff --git a/fpga/common/remote_access.v b/fpga/common/remote_access.v
index 33fc99b..1482cfb 100644
--- a/fpga/common/remote_access.v
+++ b/fpga/common/remote_access.v
@@ -50,10 +50,13 @@ module remote_access(
 	output remote_access_lcd_rs_out,
 	output remote_access_lcd_rw_out,
 	output remote_access_lcd_enable_out);
+
+	parameter RAM_ADDR_BITS = 14;
 	
 	reg [7:0] remote_access_4_bit_input_reg;
 	reg [7:0] remote_access_8_bit_input_reg;
 	reg [15:0] remote_access_16_bit_input_reg;
+	reg [15:0] remote_access_data_ram_size_reg = (2**RAM_ADDR_BITS);
 	reg [3:0] remote_access_lcd_data_out_reg;
 	reg remote_access_lcd_rs_out_reg;
 	reg remote_access_lcd_rw_out_reg;
@@ -197,7 +200,7 @@ module remote_access(
 	reg [13:0] data_storage_addra_reg;
 	reg data_storage_write_enable_reg;
 
-	data_storage data_storage(.clka(data_storage_clka), .dina(data_storage_dina), .addra(data_storage_addra), 
+	data_storage #(RAM_ADDR_BITS) data_storage(.clka(data_storage_clka), .dina(data_storage_dina), .addra(data_storage_addra), 
 		.wea(data_storage_write_enable), .douta(data_storage_data_out));
 	
 	assign data_storage_clka = (data_storage_remote_enable) ? main_fifty_clock : sram_clock_in;
@@ -258,7 +261,6 @@ module remote_access(
 	
 	reg enable_remote_access_input = 1;
 	reg remote_access_input_enable_prev = 0;
-	reg prev_was_carriage_return = 0;
 	
 	reg [7:0] lcd_display_string [31:0];
 	
@@ -370,7 +372,7 @@ module remote_access(
 
 				if ((transmit_dsp_rx_complete == 1) && (transmit_dsp_rx_complete_done == 0)) begin
 					TxD_data = 77;
-												
+
 					TxD_start = 1;
 					tx_toggle = 1;
 					
@@ -385,13 +387,13 @@ module remote_access(
 					end else begin
 						data_storage_write_enable_reg = 0;
 						TxD_data = data_storage_data_out;
-													
+
 						TxD_start = 1;
 						tx_toggle = 1;
 						
 						transmit_dsp_status_counter = transmit_dsp_status_counter + 1;
 						data_storage_addra_reg = transmit_dsp_status_counter;
-						if (transmit_dsp_status_counter > 16384) begin
+						if (transmit_dsp_status_counter >= (2**RAM_ADDR_BITS)) begin
 							transmit_dsp_status_done = 1;
 							data_storage_write_enable_reg = 1'bz;
 							data_storage_addra_reg = 14'bz;
@@ -571,164 +573,165 @@ module remote_access(
 			transmit_dsp_status = 1;
 		end
 	
-		if (RxD_data_ready == 1) begin		
+		if (RxD_data_ready == 1) begin
 			if (serial_character_received == 0) begin
 				serial_rx_data_reg = RxD_data;
 				serial_rx_strobe_reg = 1;		// Signal new data...
 				if (seize_serial_tx == 0) begin
-					// Parse the command and see what it is
-					serial_character_received = 1;
-					if (RxD_data == 13) begin
-						// Carriage Return!  The serial_command_buffer holds the command!  Parse it!
-						if (next_byte_is_command == 0) begin
-							if (serial_command_buffer == 65) begin
-								// Display update requested
-								next_byte_is_command = 1;
-								serial_update_counter = 0;
-								next_byte_is_command_prev_command = 65;
-							end
+					if (next_byte_is_command_prev_command == 77) begin
+						// DSP input data
+						if (dsp_update_counter < (2**RAM_ADDR_BITS)) begin
+							data_storage_remote_enable = 1;
+							data_storage_addra_reg = dsp_update_counter;
+							data_storage_dina_reg = serial_rx_data_reg;
+							data_storage_write_enable_reg = 1;
+							data_write_timer = 3;
+							dsp_update_counter = dsp_update_counter + 1;
 							
-							if (serial_command_buffer == 66) begin
-								// 8 bit input update
-								if (enable_remote_access_input == 1) begin
+							// TESTING ONLY!!!
+							//if (dsp_update_counter < 17) begin
+							//	received_lcd_display_string[dsp_update_counter - 1] = serial_command_buffer;
+							//end
+
+							if (dsp_update_counter >= (2**RAM_ADDR_BITS)) begin
+								next_byte_is_command = 0;
+								data_storage_write_enable_reg = 0;
+								data_storage_remote_enable = 0;
+								sram_available_reg = 1;
+								data_storage_write_enable_reg = 1'bz;
+								data_storage_addra_reg = 14'bz;
+								waiting_on_dsp_processing = 1;
+								transmit_dsp_rx_complete = 1;
+								next_byte_is_command_prev_command = 0;
+								
+								// TESTING ONLY!!!
+								//transmit_dsp_status = 1;
+							end
+						end
+					end else begin
+						// Parse the command and see what it is
+						serial_character_received = 1;
+						if (serial_rx_data_reg == 13) begin
+							// Carriage Return!  The serial_command_buffer holds the command!  Parse it!
+							if (next_byte_is_command == 0) begin
+								if (serial_command_buffer == 65) begin
+									// Display update requested
 									next_byte_is_command = 1;
 									serial_update_counter = 0;
-									next_byte_is_command_prev_command = 66;
+									next_byte_is_command_prev_command = 65;
 								end
-							end
-							
-							if (serial_command_buffer == 67) begin
-								// 16 bit input update
-								next_byte_is_command = 1;
-								serial_update_counter = 0;
-								next_byte_is_command_prev_command = 67;
-							end
-							
-							if (serial_command_buffer == 68) begin
-								// 8 bit output status
-								transmit_8_bit_status = 1;
-							end
-							
-							if (serial_command_buffer == 69) begin
-								// 16 bit output status
-								transmit_16_bit_status = 1;
-							end
-							
-							if (serial_command_buffer == 70) begin
-								// System status
-								transmit_main_status = 1;
-							end
-							
-							if (serial_command_buffer == 71) begin
-								// Simulate center button press
-								enable_remote_access_input = !enable_remote_access_input;
-							end
-							
-							if (serial_command_buffer == 72) begin
-								// Local input status
-								transmit_input_status = 1;
-							end
-							
-							if (serial_command_buffer == 73) begin
-								// 4 bit input update
-								if (enable_remote_access_input == 1) begin
+								
+								if (serial_command_buffer == 66) begin
+									// 8 bit input update
+									if (enable_remote_access_input == 1) begin
+										next_byte_is_command = 1;
+										serial_update_counter = 0;
+										next_byte_is_command_prev_command = 66;
+									end
+								end
+								
+								if (serial_command_buffer == 67) begin
+									// 16 bit input update
 									next_byte_is_command = 1;
 									serial_update_counter = 0;
-									next_byte_is_command_prev_command = 73;
+									next_byte_is_command_prev_command = 67;
 								end
-							end
-							
-							if (serial_command_buffer == 74) begin
-								// 4 bit output status
-								transmit_4_bit_status = 1;
-							end
-							
-							if (serial_command_buffer == 75) begin
-								// Transmit the contents of the LCD...
-								transmit_lcd_status = 1;
-							end
-							
-							if (serial_command_buffer == 76) begin
-								// Transmit the contents of the LCD...
-								transmit_all_data_state = 1;
-								transmit_lcd_status = 1;
-							end
-							
-							if (serial_command_buffer == 77) begin
-								// Receive offline DSP data
-								next_byte_is_command = 1;
-								dsp_update_counter = 0;
-								next_byte_is_command_prev_command = 77;
-							end
-							
-							if (serial_command_buffer == 78) begin
-								// Transmit the contents of RAM...
-								transmit_dsp_status = 1;
-							end
-						end else begin														
-							if (next_byte_is_command == 1) begin
-								// The previous byte was the command--now load in the data!
-								if (next_byte_is_command_prev_command == 65) begin
-									if (serial_update_counter < 32) begin
-										received_lcd_display_string[serial_update_counter] = serial_command_buffer;
-										serial_update_counter = serial_update_counter + 1;
-									end else begin
-										update_lcd_display = 1;
-										serial_command_timer = 255;
-										next_byte_is_command = 0;
-									end
+								
+								if (serial_command_buffer == 68) begin
+									// 8 bit output status
+									transmit_8_bit_status = 1;
 								end
 								
-								// 4 bit input update
-								if (next_byte_is_command_prev_command == 73) begin
-									remote_access_4_bit_input_reg = serial_command_buffer;
-									next_byte_is_command = 0;
+								if (serial_command_buffer == 69) begin
+									// 16 bit output status
+									transmit_16_bit_status = 1;
 								end
 								
-								// 8 bit input update
-								if (next_byte_is_command_prev_command == 66) begin
-									remote_access_8_bit_input_reg = serial_command_buffer;
-									next_byte_is_command = 0;
+								if (serial_command_buffer == 70) begin
+									// System status
+									transmit_main_status = 1;
 								end
 								
-								// 16 bit input update
-								if (next_byte_is_command_prev_command == 67) begin
-									if (serial_update_counter == 0) begin
-										remote_access_16_bit_input_reg[15:8] = serial_command_buffer;
-										serial_update_counter = 1;
-									end else begin
-										remote_access_16_bit_input_reg[7:0] = serial_command_buffer;
-										next_byte_is_command = 0;
+								if (serial_command_buffer == 71) begin
+									// Simulate center button press
+									enable_remote_access_input = !enable_remote_access_input;
+								end
+								
+								if (serial_command_buffer == 72) begin
+									// Local input status
+									transmit_input_status = 1;
+								end
+								
+								if (serial_command_buffer == 73) begin
+									// 4 bit input update
+									if (enable_remote_access_input == 1) begin
+										next_byte_is_command = 1;
+										serial_update_counter = 0;
+										next_byte_is_command_prev_command = 73;
 									end
 								end
 								
-								// DSP input data
-								if (next_byte_is_command_prev_command == 77) begin
-									if (dsp_update_counter < 16384) begin
-										data_storage_remote_enable = 1;
-										data_storage_addra_reg = dsp_update_counter;
-										data_storage_dina_reg = serial_command_buffer;
-										data_storage_write_enable_reg = 1;
-										data_write_timer = 3;
-										dsp_update_counter = dsp_update_counter + 1;
-										
-										// TESTING ONLY!!!
-										//if (dsp_update_counter < 17) begin
-										//	received_lcd_display_string[dsp_update_counter - 1] = serial_command_buffer;
-										//end
-
-										if (dsp_update_counter >= 16384) begin
+								if (serial_command_buffer == 74) begin
+									// 4 bit output status
+									transmit_4_bit_status = 1;
+								end
+								
+								if (serial_command_buffer == 75) begin
+									// Transmit the contents of the LCD...
+									transmit_lcd_status = 1;
+								end
+								
+								if (serial_command_buffer == 76) begin
+									// Transmit the contents of the LCD...
+									transmit_all_data_state = 1;
+									transmit_lcd_status = 1;
+								end
+								
+								if (serial_command_buffer == 77) begin
+									// Receive offline DSP data
+									next_byte_is_command = 1;
+									dsp_update_counter = 0;
+									next_byte_is_command_prev_command = 77;
+								end
+								
+								if (serial_command_buffer == 78) begin
+									// Transmit the contents of RAM...
+									transmit_dsp_status = 1;
+								end
+							end else begin
+								if (next_byte_is_command == 1) begin
+									// The previous byte was the command--now load in the data!
+									if (next_byte_is_command_prev_command == 65) begin
+										if (serial_update_counter < 32) begin
+											received_lcd_display_string[serial_update_counter] = serial_command_buffer;
+											serial_update_counter = serial_update_counter + 1;
+										end else begin
+											update_lcd_display = 1;
+											serial_command_timer = 255;
+											next_byte_is_command = 0;
+										end
+									end
+									
+									// 4 bit input update
+									if (next_byte_is_command_prev_command == 73) begin
+										remote_access_4_bit_input_reg = serial_command_buffer;
+										next_byte_is_command = 0;
+									end
+									
+									// 8 bit input update
+									if (next_byte_is_command_prev_command == 66) begin
+										remote_access_8_bit_input_reg = serial_command_buffer;
+										next_byte_is_command = 0;
+									end
+									
+									// 16 bit input update
+									if (next_byte_is_command_prev_command == 67) begin
+										if (serial_update_counter == 0) begin
+											remote_access_16_bit_input_reg[15:8] = serial_command_buffer;
+											serial_update_counter = 1;
+										end else begin
+											remote_access_16_bit_input_reg[7:0] = serial_command_buffer;
 											next_byte_is_command = 0;
-											data_storage_write_enable_reg = 0;
-											data_storage_remote_enable = 0;
-											sram_available_reg = 1;
-											data_storage_write_enable_reg = 1'bz;
-											data_storage_addra_reg = 14'bz;
-											waiting_on_dsp_processing = 1;
-											transmit_dsp_rx_complete = 1;
-											
-											// TESTING ONLY!!!
-											//transmit_dsp_status = 1;
 										end
 									end
 								end
@@ -740,12 +743,6 @@ module remote_access(
 				//if (RxD_data != 10) begin		// Ignore linefeeds
 					serial_command_buffer = RxD_data;
 				//end
-				
-				if (RxD_data == 13) begin
-					prev_was_carriage_return = 1;
-				end else begin
-					prev_was_carriage_return = 0;
-				end
 			
 				serial_receiver_toggler = serial_receiver_toggler + 1;
 			end
diff --git a/fpga/xilinx/digilent/spartan_6/s6_remotefpga_test/data_storage.v b/fpga/xilinx/digilent/spartan_6/s6_remotefpga_test/data_storage.v
index f1d10be..60c1dff 100644
--- a/fpga/xilinx/digilent/spartan_6/s6_remotefpga_test/data_storage.v
+++ b/fpga/xilinx/digilent/spartan_6/s6_remotefpga_test/data_storage.v
@@ -13,20 +13,20 @@ module data_storage(
 	input wea,
 	output reg [7:0] douta);
 
-   parameter RAM_WIDTH = 8;
-   parameter RAM_ADDR_BITS = 14;
- 
-   // Xilinx specific directive
-   (* RAM_STYLE="BLOCK" *)
-
-   reg [RAM_WIDTH-1:0] data_storage_ram [(2**RAM_ADDR_BITS)-1:0];
-
-   always @(posedge clka) begin
-      if (wea) begin
+	parameter RAM_ADDR_BITS = 14;
+	parameter RAM_WIDTH = 8;
+	
+	// Xilinx specific directive
+	(* RAM_STYLE="BLOCK" *)
+	
+	reg [RAM_WIDTH-1:0] data_storage_ram [(2**RAM_ADDR_BITS)-1:0];
+	
+	always @(posedge clka) begin
+	if (wea) begin
 			data_storage_ram[addra] <= dina;
 			douta <= dina;
-      end else begin
-			douta <= data_storage_ram[addra];					
+	end else begin
+			douta <= data_storage_ram[addra];
 		end
 	end