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Code Issues Releases Wiki Activity

NES: [PPU] align video clock to system clock

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This commit is contained in:
Gyorgy Szombathelyi
2020-02-20 11:28:55 +01:00
parent 687723ac05
commit 002b091ddb
1 changed files with 2 additions and 2 deletions
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4
cores/nes/src/ppu.sv
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@@ -160,7 +160,7 @@ assign at_last_cycle_group = (cycle[8:3] == 42);
// Every second pre-render frame is only 340 cycles instead of 341.
assign short_frame = end_of_line & skip_pixel;
wire skip_pixel = is_pre_render && ~even_frame_toggle && is_rendering;
wire skip_pixel = is_pre_render && ~even_frame_toggle && is_rendering && skip_en;
assign end_of_line = at_last_cycle_group && (cycle[3:0] == (skip_pixel ? 3 : 4));
// Confimed with Visual 2C02
@@ -194,7 +194,7 @@ end else if (ce && end_of_line) begin
// Visual 2C02 shows the register flipping here
if (scanline == 255)
even_frame_toggle <= skip_en ? ~even_frame_toggle : 1'b1;
even_frame_toggle <= ~even_frame_toggle;
end
endmodule // ClockGen