diff options
Diffstat (limited to 'common/8b10b.c')
| -rw-r--r-- | common/8b10b.c | 233 |
1 files changed, 233 insertions, 0 deletions
diff --git a/common/8b10b.c b/common/8b10b.c new file mode 100644 index 0000000..a32b7f2 --- /dev/null +++ b/common/8b10b.c @@ -0,0 +1,233 @@ + +#include <assert.h> +#include <stdio.h> + +#include "8b10b.h" + +/* Ignore warnings about some of the following arrays being unused. They will be removed by the linker. I want to keep + * them here for future reference. */ +#pragma GCC diagnostic ignored "-Wunused-const-variable=0" +static const struct entry map_5b6b[32] = { + {0b100111, 0b011000, 2}, /* D.00 */ + {0b011101, 0b100010, 2}, /* D.01 */ + {0b101101, 0b010010, 2}, /* D.02 */ + {0b110001, 0b110001, 0}, /* D.03 */ + {0b110101, 0b001010, 2}, /* D.04 */ + {0b101001, 0b101001, 0}, /* D.05 */ + {0b011001, 0b011001, 0}, /* D.06 */ + {0b111000, 0b000111, 0}, /* D.07 */ + {0b111001, 0b000110, 2}, /* D.08 */ + {0b100101, 0b100101, 0}, /* D.09 */ + {0b010101, 0b010101, 0}, /* D.10 */ + {0b110100, 0b110100, 0}, /* D.11 */ + {0b001101, 0b001101, 0}, /* D.12 */ + {0b101100, 0b101100, 0}, /* D.13 */ + {0b011100, 0b011100, 0}, /* D.14 */ + {0b010111, 0b101000, 2}, /* D.15 */ + {0b011011, 0b100100, 2}, /* D.16 */ + {0b100011, 0b100011, 0}, /* D.17 */ + {0b010011, 0b010011, 0}, /* D.18 */ + {0b110010, 0b110010, 0}, /* D.19 */ + {0b001011, 0b001011, 0}, /* D.20 */ + {0b101010, 0b101010, 0}, /* D.21 */ + {0b011010, 0b011010, 0}, /* D.22 */ + {0b111010, 0b000101, 2}, /* D.23 */ + {0b110011, 0b001100, 2}, /* D.24 */ + {0b100110, 0b100110, 0}, /* D.25 */ + {0b010110, 0b010110, 0}, /* D.26 */ + {0b110110, 0b001001, 2}, /* D.27 */ + {0b001110, 0b001110, 0}, /* D.28 */ + {0b101110, 0b010001, 2}, /* D.29 */ + {0b011110, 0b100001, 2}, /* D.30 */ + {0b101011, 0b010100, 2} /* D.31 */ +}; + +static const int8_t map_6b5b[64] = { + [0b000101] = 23, /* rd = +1 */ + [0b000110] = 8, /* rd = +1 */ + [0b000111] = 7, /* rd = +1 */ + [0b001001] = 27, /* rd = +1 */ + [0b001010] = 4, /* rd = +1 */ + [0b001011] = 20, /* rd = +1 */ + [0b001100] = 24, /* rd = +1 */ + [0b001101] = 12, /* rd = +1 */ + [0b001101] = 12, /* rd = -1 */ + [0b001110] = 28, /* rd = +1 */ + [0b010001] = 29, /* rd = +1 */ + [0b010010] = 2, /* rd = +1 */ + [0b010011] = 18, /* rd = +1 */ + [0b010100] = 31, /* rd = +1 */ + [0b010101] = 10, /* rd = +1 */ + [0b010101] = 10, /* rd = -1 */ + [0b010110] = 26, /* rd = +1 */ + [0b010111] = 15, /* rd = -1 */ + [0b011000] = -1, /* rd = +1 */ + [0b011001] = 6, /* rd = +1 */ + [0b011010] = 22, /* rd = +1 */ + [0b011011] = 16, /* rd = -1 */ + [0b011100] = 14, /* rd = -1 */ + [0b011101] = 1, /* rd = -1 */ + [0b011110] = 30, /* rd = -1 */ + [0b100001] = 30, /* rd = +1 */ + [0b100010] = 1, /* rd = +1 */ + [0b100011] = 17, /* rd = -1 */ + [0b100100] = 16, /* rd = +1 */ + [0b100101] = 9, /* rd = -1 */ + [0b100110] = 25, /* rd = -1 */ + [0b100111] = -1, /* rd = -1 */ + [0b101000] = 15, /* rd = +1 */ + [0b101001] = 5, /* rd = -1 */ + [0b101010] = 21, /* rd = -1 */ + [0b101011] = 31, /* rd = -1 */ + [0b101100] = 13, /* rd = -1 */ + [0b101101] = 2, /* rd = -1 */ + [0b101110] = 29, /* rd = -1 */ + [0b110001] = 3, /* rd = -1 */ + [0b110010] = 19, /* rd = -1 */ + [0b110011] = 24, /* rd = -1 */ + [0b110100] = 11, /* rd = -1 */ + [0b110101] = 4, /* rd = -1 */ + [0b110110] = 27, /* rd = -1 */ + [0b111000] = 7, /* rd = -1 */ + [0b111001] = 8, /* rd = -1 */ + [0b111010] = 23 /* rd = -1 */ +}; + +static const struct entry K28 = {0b001111, 0b110000}; + +static const struct entry map_3b4b_d[8] = { + {0b1011, 0b0100, 2}, /* D.x.0 */ + {0b1001, 0b1001, 0}, /* D.x.1 */ + {0b0101, 0b0101, 0}, /* D.x.2 */ + {0b1100, 0b0011, 0}, /* D.x.3 */ + {0b1101, 0b0010, 2}, /* D.x.4 */ + {0b1010, 0b1010, 0}, /* D.x.5 */ + {0b0110, 0b0110, 0}, /* D.x.6 */ + {0b1110, 0b0001, 2} /* D.x.P7 */ +}; + +static const struct entry Dx_A7 = {0b0111, 0b1000, 2}; + +static const struct entry map_3b4b_k[8] = { + {0b1011, 0b0100}, /* K.x.0 */ + {0b0110, 0b1001}, /* K.x.1 */ + {0b1010, 0b0101}, /* K.x.2 */ + {0b1100, 0b0011}, /* K.x.3 */ + {0b1101, 0b0010}, /* K.x.4 */ + {0b0101, 0b1010}, /* K.x.5 */ + {0b1001, 0b0110}, /* K.x.6 */ + {0b0111, 0b1000} /* K.x.7 */ +}; + +static const int8_t map_4b3b[16] = { + [0b0001] = 7, /* DxP7 rd = +1 */ + [0b0010] = 4, /* rd = +1 */ + [0b0011] = 3, /* rd = +1 */ + [0b0100] = -1, /* rd = +1 */ + [0b0101] = 2, /* rd = -1 */ + [0b0110] = 6, /* rd = -1 */ + [0b0111] = 7, /* DxA7 rd = -1 */ + [0b1000] = 7, /* DxA7 rd = +1 */ + [0b1001] = 1, /* rd = -1 */ + [0b1010] = 5, /* rd = -1 */ + [0b1011] = -1, /* rd = -1 */ + [0b1100] = 3, /* rd = -1 */ + [0b1101] = 4, /* rd = -1 */ + [0b1110] = 7, /* DxP7 rd = -1 */ + [0b1111] = 0, /* invalid */ + [0b0000] = 0 /* invalid */ +}; + +static const uint16_t k_sym_map[K_CODES_LAST] = { + [K28_0] = 0b0011110100, + [K28_1] = 0b0011111001, + [K28_2] = 0b0011110101, + [K28_3] = 0b0011110011, + [K28_4] = 0b0011110010, + [K28_5] = 0b0011111010, + [K28_6] = 0b0011110110, + [K28_7] = 0b0011111000, + [K23_7] = 0b1110101000, + [K27_7] = 0b1101101000, + [K29_7] = 0b1011101000, + [K30_7] = 0b0111101000 +}; + +void xfr_8b10b_reset(struct state_8b10b_dec *st) { + st->rx = 0; + st->bit_ctr = 0; /* unsynchronized */ +} + +int xfr_8b10b_feed_bit(struct state_8b10b_dec *st, int bit) { + uint32_t pattern = st->rx = (st->rx<<1 | !!bit) & 0x3ff; + uint16_t comma = k_sym_map[K28_1]; + if (pattern == comma || pattern == ((~comma)&0x3ff)) { + st->bit_ctr = 1; + return -K28_1; + } + + if (st->bit_ctr == 10) { + st->bit_ctr = 1; + + for (int i=1; i<sizeof(k_sym_map)/sizeof(k_sym_map[0]); i++) { + if (pattern == k_sym_map[i]) + return -i; + } + + int p3b = map_4b3b[pattern & 0xf]; + int p5b = map_6b5b[pattern >> 4]; + + if (p3b == 0 || p5b == 0) + return -DECODING_ERROR; + + p3b = (p3b == -1) ? 0 : p3b; + p5b = (p5b == -1) ? 0 : p5b; + return p3b<<5 | p5b; + + } else if (st->bit_ctr > 0) { + st->bit_ctr++; + } /* else we do not have sync yet */ + return -DECODING_IN_PROGRESS; +} + +bool xfr_8b10b_has_sync(struct state_8b10b_dec *st) { + return st->bit_ctr != 0; +} + +void xfr_8b10b_encode_reset(struct state_8b10b_enc *st) { + st->rd = -1; +} + +int xfr_8b10b_encode(struct state_8b10b_enc *st, int data) { + if (data < 0) { + if (-data >= sizeof(k_sym_map)/sizeof(k_sym_map[0])) + return -EINVAL; + + return k_sym_map[-data]; + } + + if (data > 255) + return -EINVAL; + + int p5b = data&0x1f, p3b = data>>5; + //fprintf(stderr, "\nrd %d data %x p5b %d p3b %d\n", st->rd, data, p5b, p3b); + + int x5b = (st->rd == -1) ? map_5b6b[p5b].rd_neg : map_5b6b[p5b].rd_pos; + st->rd -= map_5b6b[p5b].disp * st->rd; + //fprintf(stderr, "\nnow: rd %d data %x p5b %d p3b %d\n", st->rd, data, p5b, p3b); + //assert(st->rd == -1 || st->rd == 1); + + int x3b = (st->rd == -1) ? map_3b4b_d[p3b].rd_neg : map_3b4b_d[p3b].rd_pos; + if (p3b == 7) { + if ( (st->rd == -1 && (p5b == 17 || p5b == 18 || p5b == 20)) + || (st->rd == 1 && (p5b == 11 || p5b == 13 || p5b == 14))) { + //fprintf(stderr, "A7 override\n"); + x3b = (st->rd == -1) ? Dx_A7.rd_neg : Dx_A7.rd_pos; + } + } + st->rd -= map_3b4b_d[p3b].disp * st->rd; /* D.x.A7 and D.x.P7 both have parity 2 */ + //assert(st->rd == -1 || st->rd == 1); + + return x5b<<4 | x3b; +} + |