1.1 --- /dev/null Thu Jan 01 00:00:00 1970 +0000
1.2 +++ b/examples/vga-dual/vga.h Tue Oct 23 21:34:54 2018 +0200
1.3 @@ -0,0 +1,58 @@
1.4 +/*
1.5 + * Generate a VGA signal using a PIC32 microcontroller.
1.6 + *
1.7 + * Copyright (C) 2017, 2018 Paul Boddie <paul@boddie.org.uk>
1.8 + *
1.9 + * This program is free software: you can redistribute it and/or modify
1.10 + * it under the terms of the GNU General Public License as published by
1.11 + * the Free Software Foundation, either version 3 of the License, or
1.12 + * (at your option) any later version.
1.13 + *
1.14 + * This program is distributed in the hope that it will be useful,
1.15 + * but WITHOUT ANY WARRANTY; without even the implied warranty of
1.16 + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
1.17 + * GNU General Public License for more details.
1.18 + *
1.19 + * You should have received a copy of the GNU General Public License
1.20 + * along with this program. If not, see <http://www.gnu.org/licenses/>.
1.21 + */
1.22 +
1.23 +#ifndef __VGA_H__
1.24 +#define __VGA_H__
1.25 +
1.26 +#define LINE_LENGTH 160 /* pixels */
1.27 +#define LINE_COUNT 256 /* distinct display lines */
1.28 +#define LINE_MULTIPLIER 2
1.29 +
1.30 +#define ZERO_LENGTH 1 /* pixels */
1.31 +
1.32 +/* 24MHz cycle measurements. */
1.33 +
1.34 +#define HFREQ_LIMIT 643
1.35 +#define HSYNC_START 460
1.36 +#define HSYNC_LIMIT 64
1.37 +#define HSYNC_END (HSYNC_START + HSYNC_LIMIT)
1.38 +
1.39 +/* Horizontal lines, back porch end. */
1.40 +
1.41 +#define VISIBLE_START 70
1.42 +#define VFP_START (VISIBLE_START + LINE_MULTIPLIER * LINE_COUNT)
1.43 +
1.44 +/* Horizontal lines, front porch end. */
1.45 +
1.46 +#define VSYNC_START 620
1.47 +
1.48 +/* Horizontal lines, back porch start. */
1.49 +
1.50 +#define VSYNC_END 622
1.51 +
1.52 +/* Framebuffer properties. */
1.53 +
1.54 +#define SCREEN_SIZE (LINE_LENGTH * LINE_COUNT)
1.55 +
1.56 +/* Transfer and pixel allocation properties. */
1.57 +
1.58 +#define TRANSFER_CELL_SIZE (LINE_LENGTH / 2)
1.59 +#define CELL_SIZE 4
1.60 +
1.61 +#endif /* __VGA_H__ */