verilog: added comments

This commit is contained in:
Steven Hugg 2020-05-13 12:50:16 -05:00
parent 7371b71648
commit 63a5875283
2 changed files with 14 additions and 6 deletions

View File

@ -146,6 +146,7 @@ module racing_game_cpu_top(clk, reset, hsync, vsync, hpaddle, vpaddle, rgb);
wire r = display_on && (player_gfx || enemy_gfx || track_shoulder);
wire g = display_on && (player_gfx || track_gfx);
wire b = display_on && (enemy_gfx || track_shoulder);
// RGBI (in IBGR order, intensity is 4th bit)
assign rgb = {1'b0,b,g,r};
//////////// CPU program code

View File

@ -7,13 +7,15 @@ A simple test pattern using the hvsync_generator module.
module test_hvsync_top(clk, reset, hsync, vsync, rgb);
input clk, reset;
output hsync, vsync;
output [2:0] rgb;
wire display_on;
wire [8:0] hpos;
wire [8:0] vpos;
input clk, reset; // clock and reset signals (input)
output hsync, vsync; // H/V sync signals (output)
output [2:0] rgb; // RGB output (BGR order)
wire display_on; // display_on signal
wire [8:0] hpos; // 9-bit horizontal position
wire [8:0] vpos; // 9-bit vertical position
// Include the H-V Sync Generator module and
// wire it to inputs, outputs, and wires.
hvsync_generator hvsync_gen(
.clk(clk),
.reset(0),
@ -24,9 +26,14 @@ module test_hvsync_top(clk, reset, hsync, vsync, rgb);
.vpos(vpos)
);
// Assign each color bit to individual wires.
wire r = display_on && (((hpos&7)==0) || ((vpos&7)==0));
wire g = display_on && vpos[4];
wire b = display_on && hpos[4];
// Concatenation operator merges the red, green, and blue signals
// into a single 3-bit vector, which is assigned to the 'rgb'
// output. The IDE expects this value in BGR order.
assign rgb = {b,g,r};
endmodule