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Simplify the D-Star fast data support.
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g4klx committed Dec 14, 2020
1 parent c06a836 commit 9440b43
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Showing 3 changed files with 15 additions and 30 deletions.
38 changes: 12 additions & 26 deletions DStarRX.cpp
@@ -1,5 +1,5 @@
/*
* Copyright (C) 2009-2017 by Jonathan Naylor G4KLX
* Copyright (C) 2009-2017,2020 by Jonathan Naylor G4KLX
* Copyright (C) 2017 by Andy Uribe CA6JAU
*
* This program is free software; you can redistribute it and/or modify
Expand Down Expand Up @@ -31,13 +31,13 @@ const uint32_t INC = PLLINC / 32U;
const unsigned int MAX_SYNC_BITS = 100U * DSTAR_DATA_LENGTH_BITS;

// D-Star bit order version of 0x55 0x55 0x6E 0x0A
const uint32_t FRAME_SYNC_DATA = 0x00557650U;
const uint32_t FRAME_SYNC_MASK = 0x00FFFFFFU;
const uint64_t FRAME_SYNC_DATA = 0x0000000000557650U;
const uint64_t FRAME_SYNC_MASK = 0x0000000000FFFFFFU;
const uint8_t FRAME_SYNC_ERRS = 2U;

// D-Star bit order version of 0x55 0x2D 0x16
const uint32_t DATA_SYNC_DATA = 0x00AAB468U;
const uint32_t DATA_SYNC_MASK = 0x00FFFFFFU;
const uint64_t DATA_SYNC_DATA = 0x0000000000AAB468U;
const uint64_t DATA_SYNC_MASK = 0x0000000000FFFFFFU;
const uint8_t DATA_SYNC_ERRS = 2U;

// D-Star bit order version of 0x55 0x55 0xC8 0x7A
Expand Down Expand Up @@ -242,7 +242,6 @@ m_pll(0U),
m_prev(false),
m_rxState(DSRXS_NONE),
m_patternBuffer(0x00U),
m_patternBuffer64(0x00U),
m_rxBuffer(),
m_rxBufferBits(0U),
m_dataBits(0U),
Expand All @@ -264,7 +263,6 @@ void CDStarRX::reset()
m_prev = false;
m_rxState = DSRXS_NONE;
m_patternBuffer = 0x00U;
m_patternBuffer64 = 0x00U;
m_rxBufferBits = 0U;
m_dataBits = 0U;
m_rssiAccum = 0U;
Expand Down Expand Up @@ -316,12 +314,8 @@ void CDStarRX::processNone(bool bit)
if (bit)
m_patternBuffer |= 0x01U;

m_patternBuffer64 <<= 1;
if (bit)
m_patternBuffer64 |= 0x01U;

// Fuzzy matching of the frame sync sequence
if (countBits32((m_patternBuffer & FRAME_SYNC_MASK) ^ FRAME_SYNC_DATA) <= FRAME_SYNC_ERRS) {
if (countBits64((m_patternBuffer & FRAME_SYNC_MASK) ^ FRAME_SYNC_DATA) <= FRAME_SYNC_ERRS) {
DEBUG1("DStarRX: found frame sync in None");

::memset(m_rxBuffer, 0x00U, DSTAR_FEC_SECTION_LENGTH_BYTES);
Expand All @@ -335,7 +329,7 @@ void CDStarRX::processNone(bool bit)
}

// Exact matching of the data sync bit sequence
if (countBits32((m_patternBuffer & DATA_SYNC_MASK) ^ DATA_SYNC_DATA) == 0U) {
if (countBits64((m_patternBuffer & DATA_SYNC_MASK) ^ DATA_SYNC_DATA) == 0U) {
DEBUG1("DStarRX: found data sync in None");

io.setDecode(true);
Expand Down Expand Up @@ -363,10 +357,6 @@ void CDStarRX::processHeader(bool bit)
if (bit)
m_patternBuffer |= 0x01U;

m_patternBuffer64 <<= 1;
if (bit)
m_patternBuffer64 |= 0x01U;

WRITE_BIT2(m_rxBuffer, m_rxBufferBits, bit);
m_rxBufferBits++;

Expand Down Expand Up @@ -399,15 +389,11 @@ void CDStarRX::processData(bool bit)
if (bit)
m_patternBuffer |= 0x01U;

m_patternBuffer64 <<= 1;
if (bit)
m_patternBuffer64 |= 0x01U;

WRITE_BIT2(m_rxBuffer, m_rxBufferBits, bit);
m_rxBufferBits++;

// Fuzzy matching of the end frame sequences
if (countBits64((m_patternBuffer64 & END_SYNC_MASK) ^ END_SYNC_DATA) <= END_SYNC_ERRS) {
if (countBits64((m_patternBuffer & END_SYNC_MASK) ^ END_SYNC_DATA) <= END_SYNC_ERRS) {
DEBUG1("DStarRX: Found end sync in Data");

io.setDecode(false);
Expand All @@ -422,7 +408,7 @@ void CDStarRX::processData(bool bit)
// Fuzzy matching of the data sync bit sequence
bool syncSeen = false;
if (m_rxBufferBits >= (DSTAR_DATA_LENGTH_BITS - 3U)) {
if (countBits32((m_patternBuffer & DATA_SYNC_MASK) ^ DATA_SYNC_DATA) <= DATA_SYNC_ERRS) {
if (countBits64((m_patternBuffer & DATA_SYNC_MASK) ^ DATA_SYNC_DATA) <= DATA_SYNC_ERRS) {
m_rxBufferBits = DSTAR_DATA_LENGTH_BITS;
m_dataBits = MAX_SYNC_BITS;
syncSeen = true;
Expand All @@ -432,9 +418,9 @@ void CDStarRX::processData(bool bit)
// Check to see if the sync is arriving late
if (m_rxBufferBits == DSTAR_DATA_LENGTH_BITS && !syncSeen) {
for (uint8_t i = 1U; i <= 3U; i++) {
uint32_t syncMask = DATA_SYNC_MASK >> i;
uint32_t syncData = DATA_SYNC_DATA >> i;
if (countBits32((m_patternBuffer & syncMask) ^ syncData) <= DATA_SYNC_ERRS) {
uint64_t syncMask = DATA_SYNC_MASK >> i;
uint64_t syncData = DATA_SYNC_DATA >> i;
if (countBits64((m_patternBuffer & syncMask) ^ syncData) <= DATA_SYNC_ERRS) {
m_rxBufferBits -= i;
break;
}
Expand Down
5 changes: 2 additions & 3 deletions DStarRX.h
@@ -1,5 +1,5 @@
/*
* Copyright (C) 2015,2016,2017 by Jonathan Naylor G4KLX
* Copyright (C) 2015,2016,2017,2020 by Jonathan Naylor G4KLX
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
Expand Down Expand Up @@ -40,8 +40,7 @@ class CDStarRX {
uint32_t m_pll;
bool m_prev;
DSRX_STATE m_rxState;
uint32_t m_patternBuffer;
uint64_t m_patternBuffer64;
uint64_t m_patternBuffer;
uint8_t m_rxBuffer[100U];
unsigned int m_rxBufferBits;
unsigned int m_dataBits;
Expand Down
2 changes: 1 addition & 1 deletion SerialPort.cpp
Expand Up @@ -103,7 +103,7 @@ const uint8_t MMDVM_DEBUG5 = 0xF5U;
#define HW_TYPE "MMDVM"
#endif

#define DESCRIPTION "20200901 (D-Star/DMR/System Fusion/P25/NXDN/POCSAG/FM)"
#define DESCRIPTION "20201214 (D-Star/DMR/System Fusion/P25/NXDN/POCSAG/FM)"

#if defined(GITVERSION)
#define concat(h, a, b, c) h " " a " " b " GitID #" c ""
Expand Down

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