> > // 800 X 600 @ 60Hz with a 40.000MHz pixel clock
> > module sync_const;
> >
>
> I'm going to have a look at your code tomorrow.
After putting in param instead of specparam, I finally got it to
compile, so this new version actually runs! I used "iverilog
testModule.v -o testVideo; ./testVideo" to run it. Be forewarned,
however; it takes a really, really long time for the vertical to change
(with a bunch of printing, it takes a while per horizontal scan). I need
to make this synthesizable by removing the initial block, correct?
Also, I think my clockx2 is messed up. I am correct in thinking that the
data is changed with each clock_2x change of polarity?
Besides the clock issues, this *should* work.
// 800 X 600 @ 60Hz with a 40.000MHz pixel clock
module sync_const;
parameter H_ACTIVE = 800, // pixels
H_FRONT_PORCH = 40, // pixels
H_SYNCH = 128, // pixels
H_BACK_PORCH = 88, // pixels
H_TOTAL = 1056, // pixels
V_ACTIVE = 600, // lines
V_FRONT_PORCH = 1, // lines
V_SYNCH = 4, // lines
V_BACK_PORCH = 23, // lines
V_TOTAL = 628; // lines
parameter SYNC_DATA_STATE=0,
PORCH_DATA_STATE=1,
COLOR_DATA_STATE=0;
wire clock;
wire clock_2x;
wire reset;
wire [29:0] vidout;
reg [29:0] vid_data; //29:20 R, 19:10 G, 9:0 B
reg clk;
reg [9:0] vert; //current vertical scanline location
reg [11:0] horiz; //current pixel in scanline
reg [1:0] hstate; //horizontal and vertical states
reg [1:0] vstate; //so it is easier to ref them.
assign clock=clk;
initial begin
vert<=0;
horiz<=0;
clk<=0;
hstate<=0;
vstate<=0;
end
always begin
#5 clk=~clk;
end
always @(posedge clk)
begin
horiz <= horiz + 1;
if (horiz>H_TOTAL)
begin
hstate <= 0;
horiz <=0;
vert <= vert + 1;
end else if (horiz > H_SYNCH +
H_FRONT_PORCH + H_ACTIVE)
begin
hstate <= 3;
end else if (horiz >
H_FRONT_PORCH + H_ACTIVE)
begin
hstate <= 2;
end else if (horiz > H_ACTIVE)
begin
hstate <= 1;
end
//now all the states are correct:
//0) Active - White.
//1) Front Porch.
//2) Sync signal. 0.
//3) Back Porch.
//Now set up Vert in the same way...
if (vert>V_TOTAL)
begin
hstate <= 0;
horiz <=0;
vert <=0;
vstate <=0;
// new frame
end else if (vert > V_SYNCH +
V_FRONT_PORCH + V_ACTIVE)
begin
vstate <= 3;
end else if (vert >
V_FRONT_PORCH + V_ACTIVE)
begin
vstate <= 2;
end else if (vert > V_ACTIVE)
begin
vstate <= 1;
end
//now all is ready.
//insert here the code to make colors based
//on the various values.
//example: just sync signals.
if (vstate==2) //sync state
begin
vid_data<=SYNC_DATA_STATE;
end
if (hstate==2) //sync state
begin
vid_data<=SYNC_DATA_STATE;
end
if (hstate==1 || hstate==3) //porch state
begin
vid_data<=PORCH_DATA_STATE;
end
if (vstate==1 || vstate==3) //sync state
begin
vid_data<=PORCH_DATA_STATE;
end
if (hstate==0 && vstate==0) //draw state
begin
vid_data<=COLOR_DATA_STATE;
end
$display("%g time; hstate %d, vstate %d. horiz=%d, vert=%d.\n",
$time,hstate,vstate,horiz,vert);
end
//head0_video_out u0(clock,clock_2x,reset,vidout,,,,,,,);
endmodule
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