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Work on NXDN CRC routines.

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This commit is contained in:
Jonathan Naylor
2018-02-01 19:07:55 +00:00
parent 83e97aa218
commit b69d3d247c
1 changed files with 41 additions and 48 deletions
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89
NXDNCRC.cpp
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@@ -17,6 +17,7 @@
*/ */
#include "NXDNCRC.h" #include "NXDNCRC.h"
#include "Log.h"
#include <cstdio> #include <cstdio>
#include <cassert> #include <cassert>
@@ -28,6 +29,7 @@ const uint16_t BIT_MASK_TABLE2[] = { 0x8000U, 0x4000U, 0x2000U, 0x1000U, 0x0800U
#define WRITE_BIT1(p,i,b) p[(i)>>3] = (b) ? (p[(i)>>3] | BIT_MASK_TABLE1[(i)&7]) : (p[(i)>>3] & ~BIT_MASK_TABLE1[(i)&7]) #define WRITE_BIT1(p,i,b) p[(i)>>3] = (b) ? (p[(i)>>3] | BIT_MASK_TABLE1[(i)&7]) : (p[(i)>>3] & ~BIT_MASK_TABLE1[(i)&7])
#define READ_BIT1(p,i) (p[(i)>>3] & BIT_MASK_TABLE1[(i)&7]) #define READ_BIT1(p,i) (p[(i)>>3] & BIT_MASK_TABLE1[(i)&7])
#define WRITE_BIT2(p,i,b) p[(i)>>4] = (b) ? (p[(i)>>4] | BIT_MASK_TABLE2[(i)&15]) : (p[(i)>>3] & ~BIT_MASK_TABLE2[(i)&15])
#define READ_BIT2(p,i) (p[(i)>>4] & BIT_MASK_TABLE2[(i)&15]) #define READ_BIT2(p,i) (p[(i)>>4] & BIT_MASK_TABLE2[(i)&15])
bool CNXDNCRC::checkCRC6(const unsigned char* in, unsigned int length) bool CNXDNCRC::checkCRC6(const unsigned char* in, unsigned int length)
@@ -37,6 +39,16 @@ bool CNXDNCRC::checkCRC6(const unsigned char* in, unsigned int length)
uint8_t crc[1U]; uint8_t crc[1U];
crc[0U] = createCRC6(in, length); crc[0U] = createCRC6(in, length);
uint8_t temp[1U];
temp[0U] = 0x00U;
unsigned int j = length;
for (unsigned int i = 0U; i < 6U; i++, j++) {
bool b = READ_BIT1(in, j);
WRITE_BIT1(temp, i, b);
}
LogMessage("NXDN, CRC6: new:%02X old:%02X", crc[0U], temp[0U]);
unsigned int n = length; unsigned int n = length;
for (unsigned int i = 0U; i < 6U; i++, n++) { for (unsigned int i = 0U; i < 6U; i++, n++) {
bool b1 = READ_BIT1(crc, i); bool b1 = READ_BIT1(crc, i);
@@ -69,6 +81,16 @@ bool CNXDNCRC::checkCRC12(const unsigned char* in, unsigned int length)
uint16_t crc[1U]; uint16_t crc[1U];
crc[0U] = createCRC12(in, length); crc[0U] = createCRC12(in, length);
uint16_t temp[1U];
temp[0U] = 0x00U;
unsigned int j = length;
for (unsigned int i = 0U; i < 12U; i++, j++) {
bool b = READ_BIT1(in, j);
WRITE_BIT2(temp, i, b);
}
LogMessage("NXDN, CRC12: new:%04X old:%04X", crc[0U], temp[0U]);
unsigned int n = length; unsigned int n = length;
for (unsigned int i = 0U; i < 12U; i++, n++) { for (unsigned int i = 0U; i < 12U; i++, n++) {
bool b1 = READ_BIT2(crc, i); bool b1 = READ_BIT2(crc, i);
@@ -101,6 +123,16 @@ bool CNXDNCRC::checkCRC15(const unsigned char* in, unsigned int length)
uint16_t crc[1U]; uint16_t crc[1U];
crc[0U] = createCRC15(in, length); crc[0U] = createCRC15(in, length);
uint16_t temp[1U];
temp[0U] = 0x00U;
unsigned int j = length;
for (unsigned int i = 0U; i < 15U; i++, j++) {
bool b = READ_BIT1(in, j);
WRITE_BIT2(temp, i, b);
}
LogMessage("NXDN, CRC15: new:%04X old:%04X", crc[0U], temp[0U]);
unsigned int n = length; unsigned int n = length;
for (unsigned int i = 0U; i < 15U; i++, n++) { for (unsigned int i = 0U; i < 15U; i++, n++) {
bool b1 = READ_BIT2(crc, i); bool b1 = READ_BIT2(crc, i);
@@ -128,93 +160,54 @@ void CNXDNCRC::encodeCRC15(unsigned char* in, unsigned int length)
uint8_t CNXDNCRC::createCRC6(const unsigned char* in, unsigned int length) uint8_t CNXDNCRC::createCRC6(const unsigned char* in, unsigned int length)
{ {
uint8_t crc = 0x3EU; uint8_t crc = 0x3FU;
for (unsigned int i = 0U; i < length; i++) { for (unsigned int i = 0U; i < length; i++) {
bool bit1 = READ_BIT1(in, i) != 0x00U; bool bit1 = READ_BIT1(in, i) != 0x00U;
bool bit2 = (crc & 0x20U) == 0x20U; bool bit2 = (crc & 0x20U) == 0x20U;
crc <<= 1; crc <<= 1;
if (bit1)
crc |= 0x01U;
if (bit2)
crc ^= 0x27U;
crc &= 0x3FU; crc &= 0x3FU;
}
for (unsigned int i = 0U; i < 6U; i++) { if (bit1 ^ bit2)
bool bit = (crc & 0x20U) == 0x20U;
crc <<= 1;
if (bit)
crc ^= 0x27U; crc ^= 0x27U;
} }
return (crc & 0x3FU) << 2U; return crc & 0x3FU;
} }
uint16_t CNXDNCRC::createCRC12(const unsigned char* in, unsigned int length) uint16_t CNXDNCRC::createCRC12(const unsigned char* in, unsigned int length)
{ {
uint16_t crc = 0x0D9EU; uint16_t crc = 0x0FFFU;
for (unsigned int i = 0U; i < length; i++) { for (unsigned int i = 0U; i < length; i++) {
bool bit1 = READ_BIT1(in, i) != 0x00U; bool bit1 = READ_BIT1(in, i) != 0x00U;
bool bit2 = (crc & 0x0800U) == 0x0800U; bool bit2 = (crc & 0x0800U) == 0x0800U;
crc <<= 1; crc <<= 1;
if (bit1)
crc |= 0x0001U;
if (bit2)
crc ^= 0x080FU;
crc &= 0x0FFFU; crc &= 0x0FFFU;
}
for (unsigned int i = 0U; i < 12U; i++) { if (bit1 ^ bit2)
bool bit = (crc & 0x0800U) == 0x0800U;
crc <<= 1;
if (bit)
crc ^= 0x080FU; crc ^= 0x080FU;
} }
return (crc & 0x0FFFU) << 4U; return crc & 0x0FFFU;
} }
uint16_t CNXDNCRC::createCRC15(const unsigned char* in, unsigned int length) uint16_t CNXDNCRC::createCRC15(const unsigned char* in, unsigned int length)
{ {
uint16_t crc = 0x02E4U; uint16_t crc = 0x7FFFU;
for (unsigned int i = 0U; i < length; i++) { for (unsigned int i = 0U; i < length; i++) {
bool bit1 = READ_BIT1(in, i) != 0x00U; bool bit1 = READ_BIT1(in, i) != 0x00U;
bool bit2 = (crc & 0x4000U) == 0x4000U; bool bit2 = (crc & 0x4000U) == 0x4000U;
crc <<= 1; crc <<= 1;
if (bit1)
crc |= 0x0001U;
if (bit2)
crc ^= 0x4CC5U;
crc &= 0x7FFFU; crc &= 0x7FFFU;
}
for (unsigned int i = 0U; i < 15U; i++) { if (bit1 ^ bit2)
bool bit = (crc & 0x4000U) == 0x4000U;
crc <<= 1;
if (bit)
crc ^= 0x4CC5U; crc ^= 0x4CC5U;
} }
return (crc & 0x7FFFU) << 1U; return crc & 0x7FFFU;
} }