40 lines
1.1 KiB
C++
40 lines
1.1 KiB
C++
#pragma once
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#include <cstdint>
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#include <cstddef>
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namespace acio2emu::detail {
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inline uint8_t crc4_lgp_c(uint8_t crc, const uint8_t *data, size_t len) {
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static constexpr uint8_t tbl[] = {
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0x00, 0x0D, 0x03, 0x0E,
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0x06, 0x0B, 0x05, 0x08,
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0x0C, 0x01, 0x0F, 0x02,
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0x0A, 0x07, 0x09, 0x04,
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};
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crc &= 15;
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for (size_t i = 0; i < len; i++) {
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auto b = data[i];
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crc = (((crc >> 4) ^ (tbl[(b ^ crc) & 0x0F])) >> 4) ^ tbl[(((crc >> 4) ^ (tbl[(b ^ crc) & 0x0F])) ^ (b >> 4)) & 0x0F];
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}
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return crc;
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}
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inline uint8_t crc7_lgp_48(uint8_t crc, const uint8_t *data, size_t len) {
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static constexpr uint8_t tbl[] = {
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0x00, 0x09, 0x12, 0x1B,
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0x24, 0x2D, 0x36, 0x3F,
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0x48, 0x41, 0x5A, 0x53,
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0x6C, 0x65, 0x7E, 0x77
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};
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crc &= 127;
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for (size_t i = 0; i < len; i++) {
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auto b = data[i];
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crc = (((crc >> 4) ^ (tbl[(b ^ crc) & 0x0F])) >> 4) ^ tbl[(((crc >> 4) ^ (tbl[(b ^ crc) & 0x0F])) ^ (b >> 4)) & 0x0F];
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}
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return crc;
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}
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} |