Move fillscreen to a separate moduleHEADmaster

Signed-off-by: Warrick Lo <wlo@warricklo.net>

2 files changed, 41 insertions, 46 deletions

diff --git a/task4/reuleaux.sv b/task4/reuleaux.sv
index cc89f4f..e518b63 100644
--- a/task4/reuleaux.sv
+++ b/task4/reuleaux.sv
@@ -14,7 +14,7 @@ module reuleaux(clk, rst_n, colour, centre_x, centre_y, diameter, start, done,
 	output logic [6:0] vga_y;
 	output logic [7:0] vga_x;
 
-	logic clear, ready, vga_plot_next;
+	logic clear, vga_plot_next;
 	logic [2:0] octant;
 	/* Auxiliary value for calculations. 21-bit number since we multiply
 	 * 8-bit and 13-bit numbers together. */
@@ -114,42 +114,19 @@ module reuleaux(clk, rst_n, colour, centre_x, centre_y, diameter, start, done,
 	always_ff @(posedge clk) begin
 		if (~rst_n) begin
 			done <= 1'b0;
-			ready <= 1'b0;
 
-			/* Start clearing the screen. */
-			clear <= 1'b1;
+			/* Initialise the registers for the circle algorithm. */
 			vga_x <= 8'b0;
 			vga_y <= 7'b0;
-			vga_plot <= 1'b1;
-		end
-
-		/* Clear the screen. */
-		if (clear) begin
-			if (vga_y < 120) begin
-				/* Check for one column less since it takes
-				 * one clock cycle to reset and increment. */
-				if (vga_x < 159)
-					vga_x <= vga_x + 1;
-				else begin
-					vga_x <= 8'b0;
-					vga_y <= vga_y + 1;
-				end
-			end else begin
-				clear <= 1'b0;
-				ready <= 1'b1;
-				vga_x <= 8'b0;
-				vga_y <= 7'b0;
-				vga_plot <= 1'b0;
-			end
-		/* Initialise the registers for the circle algorithm. */
-		end else if (ready && start && ~done) begin
-			ready <= 1'b0;
+			vga_plot <= 1'b0;
 			octant <= 3'b0;
 			offset_y <= 9'b0;
 			offset_x <= radius;
 			crit <= 1 - radius;
+		end
+
 		/* Draw the circle using the Bresenham circle algorithm. */
-		end else if (start && ~done) begin
+		if (start && ~done) begin
 			if (offset_y <= offset_x) begin
 				if ((vga_x_next >= 0) && (vga_x_next <= `VGA_W))
 					vga_x <= vga_x_next;
@@ -174,7 +151,6 @@ module reuleaux(clk, rst_n, colour, centre_x, centre_y, diameter, start, done,
 			/* Finished. */
 			end else begin
 				done <= 1'b1;
-				ready <= 1'b1;
 				vga_plot <= 1'b0;
 			end
 		/* Wait for start to be deasserted. */
diff --git a/task4/task4.sv b/task4/task4.sv
index 1426a72..80d278b 100644
--- a/task4/task4.sv
+++ b/task4/task4.sv
@@ -11,27 +11,46 @@ module task4(CLOCK_50, KEY, SW, LEDR, HEX0, HEX1, HEX2, HEX3, HEX4, HEX5,
 	output logic [7:0] VGA_X, VGA_R, VGA_G, VGA_B;
 	output logic [9:0] LEDR;
 
-	logic resetn, start, done;
-	logic [2:0] colour;
-	logic [6:0] center_y;
-	logic [7:0] center_x, diameter;
-
-	assign resetn = KEY[3];
-	assign start = ~KEY[0];
-	assign colour = 3'b010;
-	assign LEDR[0] = done;
-
-	assign center_x = 8'd80;
-	assign center_y = 7'd60;
-	assign diameter = SW[7:0];
+	logic resetn, done, fillscreen_start, reuleaux_start,
+		fillscreen_done, reuleaux_done, fillscreen_plot, reuleaux_plot;
+	logic [2:0] fillscreen_colour, reuleaux_colour;
+	logic [6:0] fillscreen_y, reuleaux_y;
+	logic [7:0] fillscreen_x, reuleaux_x;
 
 	vga_adapter #(.RESOLUTION("160x120")) U0(resetn, CLOCK_50,
 		VGA_COLOUR, VGA_X, VGA_Y, VGA_PLOT,
 		{VGA_R, 2'b00}, {VGA_G, 2'b00}, {VGA_B, 2'b00},
 		VGA_HS, VGA_VS, VGA_BLANK, VGA_SYNC, VGA_CLK);
 
-	reuleaux U1(CLOCK_50, resetn, colour, center_x, center_y, diameter,
-		start, done, VGA_X, VGA_Y, VGA_COLOUR, VGA_PLOT);
+	fillscreen U1(CLOCK_50, resetn, 3'b000, fillscreen_start,
+		fillscreen_done, fillscreen_vga_x, fillscreen_vga_y,
+		fillscreen_colour, fillscreen_plot);
 
-endmodule: task4
+	reuleaux U2(CLOCK_50, resetn, 3'b010, 8'd80, 7'd60, 8'd80,
+		reuleaux_start, reuleaux_done, reuleaux_x, reuleaux_y,
+		reuleaux_colour, reuleaux_plot);
 
+	assign resetn = KEY[3];
+	assign start = ~KEY[0];
+	assign LEDR[0] = done;
+
+	assign VGA_X = fillscreen_start ? fillscreen_vga_x : reuleaux_x;
+	assign VGA_Y = fillscreen_start ? fillscreen_vga_y : reuleaux_y;
+	assign VGA_COLOUR = fillscreen_start ? fillscreen_colour : reuleaux_colour;
+	assign VGA_PLOT = fillscreen_start ? fillscreen_plot : reuleaux_plot;
+
+	always_ff @(posedge CLOCK_50) begin
+		if (~resetn) begin
+			fillscreen_start <= 1'b0;
+			reuleaux_start <= 1'b1;
+			done <= 1'b0;
+		end else if (fillscreen_done) begin
+			fillscreen_start <= 1'b0;
+			reuleaux_start <= 1'b1;
+		end else if (reuleaux_done) begin
+			reuleaux_start <= 1'b0;
+			done <= 1'b1;
+		end
+	end
+
+endmodule: task4