| paul@24 | 1 | /* |
| paul@24 | 2 | * Generate a VGA signal using a PIC32 microcontroller. |
| paul@24 | 3 | * |
| paul@24 | 4 | * Copyright (C) 2017, 2018 Paul Boddie <paul@boddie.org.uk> |
| paul@24 | 5 | * |
| paul@24 | 6 | * This program is free software: you can redistribute it and/or modify |
| paul@24 | 7 | * it under the terms of the GNU General Public License as published by |
| paul@24 | 8 | * the Free Software Foundation, either version 3 of the License, or |
| paul@24 | 9 | * (at your option) any later version. |
| paul@24 | 10 | * |
| paul@24 | 11 | * This program is distributed in the hope that it will be useful, |
| paul@24 | 12 | * but WITHOUT ANY WARRANTY; without even the implied warranty of |
| paul@24 | 13 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| paul@24 | 14 | * GNU General Public License for more details. |
| paul@24 | 15 | * |
| paul@24 | 16 | * You should have received a copy of the GNU General Public License |
| paul@24 | 17 | * along with this program. If not, see <http://www.gnu.org/licenses/>. |
| paul@24 | 18 | */ |
| paul@24 | 19 | |
| paul@24 | 20 | #ifndef __VGA_H__ |
| paul@24 | 21 | #define __VGA_H__ |
| paul@24 | 22 | |
| paul@80 | 23 | #include "vga_common.h" |
| paul@80 | 24 | |
| paul@24 | 25 | #define LINE_LENGTH 160 /* pixels */ |
| paul@93 | 26 | #define LINE_COUNT 256 /* display lines per frame */ |
| paul@93 | 27 | #define FRAME_COUNT 1 /* double-buffered display */ |
| paul@24 | 28 | |
| paul@24 | 29 | /* 24MHz cycle measurements. */ |
| paul@24 | 30 | |
| paul@24 | 31 | #define HFREQ_LIMIT 643 |
| paul@24 | 32 | #define HSYNC_START 460 |
| paul@24 | 33 | #define HSYNC_LIMIT 64 |
| paul@24 | 34 | #define HSYNC_END (HSYNC_START + HSYNC_LIMIT) |
| paul@24 | 35 | |
| paul@41 | 36 | /* Framebuffer properties. */ |
| paul@24 | 37 | |
| paul@41 | 38 | #define SCREEN_SIZE (LINE_LENGTH * LINE_COUNT) |
| paul@45 | 39 | |
| paul@93 | 40 | /* A frame has an entire screen plus one line to allow horizontal scrolling, |
| paul@93 | 41 | since a horizontal scroll offset causes the final transfer line to exceed the |
| paul@93 | 42 | screen limit. */ |
| paul@93 | 43 | |
| paul@99 | 44 | #define FRAME_SIZE (SCREEN_SIZE + LINE_LENGTH) |
| paul@93 | 45 | |
| paul@45 | 46 | /* Transfer and pixel allocation properties. */ |
| paul@45 | 47 | |
| paul@45 | 48 | #define TRANSFER_CELL_SIZE LINE_LENGTH |
| paul@45 | 49 | #define CELL_SIZE LINE_LENGTH |
| paul@24 | 50 | |
| paul@24 | 51 | #endif /* __VGA_H__ */ |
