Bill Yi | 4e213d5 | 2015-06-23 13:53:11 -0700 | [diff] [blame] | 1 | /* Stuff specific to the CCSDS (255,223) RS codec |
| 2 | * (255,223) code over GF(256). Note: the conventional basis is still |
| 3 | * used; the dual-basis mappings are performed in [en|de]code_rs_ccsds.c |
| 4 | * |
| 5 | * Copyright 2003 Phil Karn, KA9Q |
| 6 | * May be used under the terms of the GNU Lesser General Public License (LGPL) |
| 7 | */ |
| 8 | typedef unsigned char data_t; |
| 9 | |
| 10 | static inline int mod255(int x){ |
| 11 | while (x >= 255) { |
| 12 | x -= 255; |
| 13 | x = (x >> 8) + (x & 255); |
| 14 | } |
| 15 | return x; |
| 16 | } |
| 17 | #define MODNN(x) mod255(x) |
| 18 | |
| 19 | extern data_t CCSDS_alpha_to[]; |
| 20 | extern data_t CCSDS_index_of[]; |
| 21 | extern data_t CCSDS_poly[]; |
| 22 | |
| 23 | #define MM 8 |
| 24 | #define NN 255 |
| 25 | #define ALPHA_TO CCSDS_alpha_to |
| 26 | #define INDEX_OF CCSDS_index_of |
| 27 | #define GENPOLY CCSDS_poly |
| 28 | #define NROOTS 32 |
| 29 | #define FCR 112 |
| 30 | #define PRIM 11 |
| 31 | #define IPRIM 116 |
| 32 | #define PAD pad |
| 33 | |