implement port percolation

[fleet.git] / ships / Video.ship

diff --git a/ships/Video.ship b/ships/Video.ship
index 03f463c..bfc01a9 100644 (file)
--- a/ships/Video.ship
+++ b/ships/Video.ship
@@ -5,7 +5,6 @@ data  in:    inX
 data  in:    inY
 data  in:    inData
 
-percolate down:       vga_clk     1
 percolate up:         vga_psave   1
 percolate up:         vga_hsync   1
 percolate up:         vga_vsync   1
@@ -54,6 +53,24 @@ percolate up:         vga_clkout  1
 
 == FPGA ==============================================================
 
+  wire vga_clk_unbuffered;  // synthesis attribute period of vga_clk_unbuffered is "40 ns";
+
+  wire vga_clk;
+  wire vga_clk_fb;
+
+  BUFG GBUF_FOR_VGA_CLOCK (.I(vga_clk_unbuffered), .O(vga_clk));
+  DCM  // 25Mhz VGA clock
+   #(
+      .CLKFX_MULTIPLY(4),
+      .CLKFX_DIVIDE(16),
+      .CLKIN_PERIOD("20 ns")
+    ) vgadcm (
+      .CLKIN (clk),
+      .CLKFB(vga_clk_fb),
+      .CLKFX (vga_clk_unbuffered),
+      .CLK0  (vga_clk_fb)
+    );
+
 
   wire [31:0] vga_pixel_addr_;
   wire        vga_pixel_r;