1 /* 2 * Generate a VGA signal using a PIC32 microcontroller. 3 * 4 * Copyright (C) 2017, 2018 Paul Boddie <paul@boddie.org.uk> 5 * 6 * This program is free software: you can redistribute it and/or modify 7 * it under the terms of the GNU General Public License as published by 8 * the Free Software Foundation, either version 3 of the License, or 9 * (at your option) any later version. 10 * 11 * This program is distributed in the hope that it will be useful, 12 * but WITHOUT ANY WARRANTY; without even the implied warranty of 13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 14 * GNU General Public License for more details. 15 * 16 * You should have received a copy of the GNU General Public License 17 * along with this program. If not, see <http://www.gnu.org/licenses/>. 18 */ 19 20 #ifndef __VGA_COMMON_H__ 21 #define __VGA_COMMON_H__ 22 23 /* Number of raster scan lines to be used. */ 24 25 #define SCANLINES 512 26 27 /* Horizontal lines, back porch end. */ 28 29 #define VISIBLE_START 72 30 31 /* Horizontal lines, front porch start. */ 32 33 #define VFP_START (VISIBLE_START + SCANLINES) 34 35 /* Horizontal lines, front porch end. */ 36 37 #define VSYNC_START 620 38 39 /* Horizontal lines, back porch start. */ 40 41 #define VSYNC_END 622 42 43 /* Define DMA channels if not indicated in the build configuration. */ 44 45 /* CPU-based transfers: no channels. */ 46 47 #ifdef TRANSFER_CPU 48 #define LINE_CHANNELS 0 49 50 /* DMA-based transfers: single channel by default. */ 51 52 #else 53 54 #ifndef LINE_CHANNELS 55 #define LINE_CHANNELS 1 56 #endif 57 58 #endif /* TRANSFER_CPU */ 59 60 #endif /* __VGA_COMMON_H__ */