X-Git-Url: https://git.zerfleddert.de/cgi-bin/gitweb.cgi/proxmark3-svn/blobdiff_plain/f83c41c75b19aa3519e88dcf6b97e85c71131edd..799b2e2e9da62c96a30e9a04da911ff3cbe8cbd9:/common/lfdemod.c diff --git a/common/lfdemod.c b/common/lfdemod.c index ffa807fe..7d40d22e 100644 --- a/common/lfdemod.c +++ b/common/lfdemod.c @@ -81,10 +81,8 @@ uint8_t Em410xDecode(uint8_t *BitStream, size_t *size, size_t *startIdx, uint32_ // otherwise could be a void with no arguments //set defaults uint32_t i = 0; - if (BitStream[1]>1){ //allow only 1s and 0s - // PrintAndLog("no data found"); - return 0; - } + if (BitStream[1]>1) return 0; //allow only 1s and 0s + // 111111111 bit pattern represent start of frame // include 0 in front to help get start pos uint8_t preamble[] = {0,1,1,1,1,1,1,1,1,1}; @@ -115,216 +113,11 @@ uint8_t Em410xDecode(uint8_t *BitStream, size_t *size, size_t *startIdx, uint32_ } //by marshmellow -//takes 3 arguments - clock, invert, maxErr as integers -//attempts to demodulate ask while decoding manchester -//prints binary found and saves in graphbuffer for further commands -int askmandemod(uint8_t *BinStream, size_t *size, int *clk, int *invert, int maxErr) -{ - size_t i; - int start = DetectASKClock(BinStream, *size, clk, 20); //clock default - if (*clk==0 || start < 0) return -3; - if (*invert != 1) *invert=0; - uint8_t initLoopMax = 255; - if (initLoopMax > *size) initLoopMax = *size; - // Detect high and lows - // 25% fuzz in case highs and lows aren't clipped [marshmellow] - int high, low; - if (getHiLo(BinStream, initLoopMax, &high, &low, 75, 75) < 1) return -2; //just noise - - // PrintAndLog("DEBUG - valid high: %d - valid low: %d",high,low); - int lastBit = 0; //set first clock check - uint16_t bitnum = 0; //output counter - uint8_t tol = 0; //clock tolerance adjust - waves will be accepted as within the clock if they fall + or - this value + clock from last valid wave - if (*clk <= 32) tol=1; //clock tolerance may not be needed anymore currently set to + or - 1 but could be increased for poor waves or removed entirely - size_t iii = 0; - //if 0 errors allowed then only try first 2 clock cycles as we want a low tolerance - if (!maxErr) initLoopMax = *clk * 2; - uint16_t errCnt = 0, MaxBits = 512; - uint16_t bestStart = start; - uint16_t bestErrCnt = 0; - // PrintAndLog("DEBUG - lastbit - %d",lastBit); - // if best start position not already found by detect clock then - if (start <= 0 || start > initLoopMax){ - bestErrCnt = maxErr+1; - // loop to find first wave that works - for (iii=0; iii < initLoopMax; ++iii){ - // if no peak skip - if (BinStream[iii] < high && BinStream[iii] > low) continue; - - lastBit = iii - *clk; - // loop through to see if this start location works - for (i = iii; i < *size; ++i) { - if ((i-lastBit) > (*clk-tol) && (BinStream[i] >= high || BinStream[i] <= low)) { - lastBit += *clk; - } else if ((i-lastBit) > (*clk+tol)) { - errCnt++; - lastBit += *clk; - } - if ((i-iii) > (MaxBits * *clk) || errCnt > maxErr) break; //got plenty of bits or too many errors - } - //we got more than 64 good bits and not all errors - if ((((i-iii)/ *clk) > (64)) && (errCnt<=maxErr)) { - //possible good read - if (!errCnt || errCnt < bestErrCnt){ - bestStart = iii; //set this as new best run - bestErrCnt = errCnt; - if (!errCnt) break; //great read - finish - } - } - errCnt = 0; - } - } - if (bestErrCnt > maxErr){ - *invert = bestStart; - *clk = iii; - return -1; - } - //best run is good enough set to best run and set overwrite BinStream - lastBit = bestStart - *clk; - errCnt = 0; - for (i = bestStart; i < *size; ++i) { - if ((BinStream[i] >= high) && ((i-lastBit) > (*clk-tol))){ - //high found and we are expecting a bar - lastBit += *clk; - BinStream[bitnum++] = *invert; - } else if ((BinStream[i] <= low) && ((i-lastBit) > (*clk-tol))){ - //low found and we are expecting a bar - lastBit += *clk; - BinStream[bitnum++] = *invert ^ 1; - } else if ((i-lastBit)>(*clk+tol)){ - //should have hit a high or low based on clock!! - //PrintAndLog("DEBUG - no wave in expected area - location: %d, expected: %d-%d, lastBit: %d - resetting search",i,(lastBit+(clk-((int)(tol)))),(lastBit+(clk+((int)(tol)))),lastBit); - if (bitnum > 0) { - BinStream[bitnum++] = 77; - errCnt++; - } - lastBit += *clk;//skip over error - } - if (bitnum >= MaxBits) break; - } - *size = bitnum; - return bestErrCnt; -} - -//by marshmellow -//encode binary data into binary manchester -int ManchesterEncode(uint8_t *BitStream, size_t size) -{ - size_t modIdx=20000, i=0; - if (size>modIdx) return -1; - for (size_t idx=0; idx < size; idx++){ - BitStream[idx+modIdx++] = BitStream[idx]; - BitStream[idx+modIdx++] = BitStream[idx]^1; - } - for (; i<(size*2); i++){ - BitStream[i] = BitStream[i+20000]; - } - return i; -} - -//by marshmellow -//take 10 and 01 and manchester decode -//run through 2 times and take least errCnt -int manrawdecode(uint8_t * BitStream, size_t *size) -{ - uint16_t bitnum=0, MaxBits = 512, errCnt = 0; - size_t i, ii; - uint16_t bestErr = 1000, bestRun = 0; - if (size == 0) return -1; - for (ii=0;ii<2;++ii){ - for (i=ii; i<*size-2; i+=2) - if (BitStream[i]==BitStream[i+1]) - errCnt++; - - if (bestErr>errCnt){ - bestErr=errCnt; - bestRun=ii; - } - errCnt=0; - } - if (bestErr<20){ - for (i=bestRun; i < *size-2; i+=2){ - if(BitStream[i] == 1 && (BitStream[i+1] == 0)){ - BitStream[bitnum++]=0; - } else if((BitStream[i] == 0) && BitStream[i+1] == 1){ - BitStream[bitnum++]=1; - } else { - BitStream[bitnum++]=77; - } - if(bitnum>MaxBits) break; - } - *size=bitnum; - } - return bestErr; -} - -//by marshmellow -//take 01 or 10 = 1 and 11 or 00 = 0 -//check for phase errors - should never have 111 or 000 should be 01001011 or 10110100 for 1010 -//decodes biphase or if inverted it is AKA conditional dephase encoding AKA differential manchester encoding -int BiphaseRawDecode(uint8_t *BitStream, size_t *size, int offset, int invert) -{ - uint16_t bitnum = 0; - uint16_t errCnt = 0; - size_t i = offset; - uint16_t MaxBits=512; - //if not enough samples - error - if (*size < 51) return -1; - //check for phase change faults - skip one sample if faulty - uint8_t offsetA = 1, offsetB = 1; - for (; i<48; i+=2){ - if (BitStream[i+1]==BitStream[i+2]) offsetA=0; - if (BitStream[i+2]==BitStream[i+3]) offsetB=0; - } - if (!offsetA && offsetB) offset++; - for (i=offset; i<*size-3; i+=2){ - //check for phase error - if (BitStream[i+1]==BitStream[i+2]) { - BitStream[bitnum++]=77; - errCnt++; - } - if((BitStream[i]==1 && BitStream[i+1]==0) || (BitStream[i]==0 && BitStream[i+1]==1)){ - BitStream[bitnum++]=1^invert; - } else if((BitStream[i]==0 && BitStream[i+1]==0) || (BitStream[i]==1 && BitStream[i+1]==1)){ - BitStream[bitnum++]=invert; - } else { - BitStream[bitnum++]=77; - errCnt++; - } - if(bitnum>MaxBits) break; - } - *size=bitnum; - return errCnt; -} - -//by marshmellow -void askAmp(uint8_t *BitStream, size_t size) -{ - int shift = 127; - int shiftedVal=0; - for(size_t i = 1; i=30) //large jump up - shift=127; - else if(BitStream[i]-BitStream[i-1]<=-20) //large jump down - shift=-127; - - shiftedVal=BitStream[i]+shift; - - if (shiftedVal>255) - shiftedVal=255; - else if (shiftedVal<0) - shiftedVal=0; - BitStream[i-1] = shiftedVal; - } - return; -} - -// demodulates strong heavily clipped samples +//demodulates strong heavily clipped samples int cleanAskRawDemod(uint8_t *BinStream, size_t *size, int clk, int invert, int high, int low) { size_t bitCnt=0, smplCnt=0, errCnt=0; uint8_t waveHigh = 0; - //PrintAndLog("clk: %d", clk); for (size_t i=0; i < *size; i++){ if (BinStream[i] >= high && waveHigh){ smplCnt++; @@ -335,7 +128,7 @@ int cleanAskRawDemod(uint8_t *BinStream, size_t *size, int clk, int invert, int if (smplCnt > clk-(clk/4)-1) { //full clock if (smplCnt > clk + (clk/4)+1) { //too many samples errCnt++; - BinStream[bitCnt++]=77; + BinStream[bitCnt++]=7; } else if (waveHigh) { BinStream[bitCnt++] = invert; BinStream[bitCnt++] = invert; @@ -371,111 +164,79 @@ int cleanAskRawDemod(uint8_t *BinStream, size_t *size, int clk, int invert, int } //by marshmellow -//takes 3 arguments - clock, invert and maxErr as integers -//attempts to demodulate ask only -int askrawdemod(uint8_t *BinStream, size_t *size, int *clk, int *invert, int maxErr, uint8_t amp) +void askAmp(uint8_t *BitStream, size_t size) +{ + for(size_t i = 1; i=30) //large jump up + BitStream[i]=127; + else if(BitStream[i]-BitStream[i-1]<=-20) //large jump down + BitStream[i]=-127; + } + return; +} + +//by marshmellow +//attempts to demodulate ask modulations, askType == 0 for ask/raw, askType==1 for ask/manchester +int askdemod(uint8_t *BinStream, size_t *size, int *clk, int *invert, int maxErr, uint8_t amp, uint8_t askType) { if (*size==0) return -1; - int start = DetectASKClock(BinStream, *size, clk, 20); //clock default - if (*clk==0 || start < 0) return -1; + int start = DetectASKClock(BinStream, *size, clk, maxErr); //clock default + if (*clk==0 || start < 0) return -3; if (*invert != 1) *invert = 0; if (amp==1) askAmp(BinStream, *size); uint8_t initLoopMax = 255; - if (initLoopMax > *size) initLoopMax=*size; + if (initLoopMax > *size) initLoopMax = *size; // Detect high and lows //25% clip in case highs and lows aren't clipped [marshmellow] int high, low; if (getHiLo(BinStream, initLoopMax, &high, &low, 75, 75) < 1) - return -1; //just noise + return -2; //just noise + size_t errCnt = 0; // if clean clipped waves detected run alternate demod - if (DetectCleanAskWave(BinStream, *size, high, low)) - return cleanAskRawDemod(BinStream, size, *clk, *invert, high, low); + if (DetectCleanAskWave(BinStream, *size, high, low)) { + errCnt = cleanAskRawDemod(BinStream, size, *clk, *invert, high, low); + if (askType) //askman + return manrawdecode(BinStream, size, 0); + else //askraw + return errCnt; + } - int lastBit = 0; //set first clock check - can go negative - size_t i, iii = 0; - size_t errCnt = 0, bitnum = 0; //output counter + int lastBit; //set first clock check - can go negative + size_t i, bitnum = 0; //output counter uint8_t midBit = 0; - size_t bestStart = start, bestErrCnt = 0; //(*size/1000); + uint8_t tol = 0; //clock tolerance adjust - waves will be accepted as within the clock if they fall + or - this value + clock from last valid wave + if (*clk <= 32) tol = 1; //clock tolerance may not be needed anymore currently set to + or - 1 but could be increased for poor waves or removed entirely size_t MaxBits = 1024; + lastBit = start - *clk; - //if 0 errors allowed then only try first 2 clock cycles as we want a low tolerance - if (!maxErr) initLoopMax = *clk * 2; - //if best start not already found by detectclock - if (start <= 0 || start > initLoopMax){ - bestErrCnt = maxErr+1; - //PrintAndLog("DEBUG - lastbit - %d",lastBit); - //loop to find first wave that works - for (iii=0; iii < initLoopMax; ++iii){ - if ((BinStream[iii] >= high) || (BinStream[iii] <= low)){ - lastBit = iii - *clk; - //loop through to see if this start location works - for (i = iii; i < *size; ++i) { - if (i-lastBit > *clk && (BinStream[i] >= high || BinStream[i] <= low)){ - lastBit += *clk; - midBit = 0; - } else if (i-lastBit > (*clk/2) && midBit == 0) { - midBit = 1; - } else if ((i-lastBit) > *clk) { - //should have hit a high or low based on clock!! - //PrintAndLog("DEBUG - no wave in expected area - location: %d, expected: %d-%d, lastBit: %d - resetting search",i,(lastBit+(clk-((int)(tol)))),(lastBit+(clk+((int)(tol)))),lastBit); - errCnt++; - lastBit += *clk;//skip over until hit too many errors - if (errCnt > maxErr) - break; - } - if ((i-iii)>(MaxBits * *clk)) break; //got enough bits - } - //we got more than 64 good bits and not all errors - if ((((i-iii)/ *clk) > 64) && (errCnt<=maxErr)) { - //possible good read - if (errCnt==0){ - bestStart=iii; - bestErrCnt=errCnt; - break; //great read - finish - } - if (errCnt maxErr){ - *invert = bestStart; - *clk = iii; - return -1; - } - //best run is good enough - set to best run and overwrite BinStream - lastBit = bestStart - *clk - 1; - errCnt = 0; - - for (i = bestStart; i < *size; ++i) { - if (i - lastBit > *clk){ + for (i = start; i < *size; ++i) { + if (i-lastBit >= *clk-tol){ if (BinStream[i] >= high) { BinStream[bitnum++] = *invert; } else if (BinStream[i] <= low) { BinStream[bitnum++] = *invert ^ 1; - } else { + } else if (i-lastBit >= *clk+tol) { if (bitnum > 0) { - BinStream[bitnum++]=77; + BinStream[bitnum++]=7; errCnt++; } + } else { //in tolerance - looking for peak + continue; } midBit = 0; lastBit += *clk; - } else if (i-lastBit > (*clk/2) && midBit == 0){ + } else if (i-lastBit >= (*clk/2-tol) && !midBit && !askType){ if (BinStream[i] >= high) { BinStream[bitnum++] = *invert; } else if (BinStream[i] <= low) { BinStream[bitnum++] = *invert ^ 1; - } else { - + } else if (i-lastBit >= *clk/2+tol) { BinStream[bitnum] = BinStream[bitnum-1]; bitnum++; + } else { //in tolerance - looking for peak + continue; } midBit = 1; } @@ -485,6 +246,98 @@ int askrawdemod(uint8_t *BinStream, size_t *size, int *clk, int *invert, int max return errCnt; } +//by marshmellow +//take 10 and 01 and manchester decode +//run through 2 times and take least errCnt +int manrawdecode(uint8_t * BitStream, size_t *size, uint8_t invert) +{ + uint16_t bitnum=0, MaxBits = 512, errCnt = 0; + size_t i, ii; + uint16_t bestErr = 1000, bestRun = 0; + if (*size < 16) return -1; + //find correct start position [alignment] + for (ii=0;ii<2;++ii){ + for (i=ii; i<*size-3; i+=2) + if (BitStream[i]==BitStream[i+1]) + errCnt++; + + if (bestErr>errCnt){ + bestErr=errCnt; + bestRun=ii; + } + errCnt=0; + } + //decode + for (i=bestRun; i < *size-3; i+=2){ + if(BitStream[i] == 1 && (BitStream[i+1] == 0)){ + BitStream[bitnum++]=invert; + } else if((BitStream[i] == 0) && BitStream[i+1] == 1){ + BitStream[bitnum++]=invert^1; + } else { + BitStream[bitnum++]=7; + } + if(bitnum>MaxBits) break; + } + *size=bitnum; + return bestErr; +} + +//by marshmellow +//encode binary data into binary manchester +int ManchesterEncode(uint8_t *BitStream, size_t size) +{ + size_t modIdx=20000, i=0; + if (size>modIdx) return -1; + for (size_t idx=0; idx < size; idx++){ + BitStream[idx+modIdx++] = BitStream[idx]; + BitStream[idx+modIdx++] = BitStream[idx]^1; + } + for (; i<(size*2); i++){ + BitStream[i] = BitStream[i+20000]; + } + return i; +} + +//by marshmellow +//take 01 or 10 = 1 and 11 or 00 = 0 +//check for phase errors - should never have 111 or 000 should be 01001011 or 10110100 for 1010 +//decodes biphase or if inverted it is AKA conditional dephase encoding AKA differential manchester encoding +int BiphaseRawDecode(uint8_t *BitStream, size_t *size, int offset, int invert) +{ + uint16_t bitnum = 0; + uint16_t errCnt = 0; + size_t i = offset; + uint16_t MaxBits=512; + //if not enough samples - error + if (*size < 51) return -1; + //check for phase change faults - skip one sample if faulty + uint8_t offsetA = 1, offsetB = 1; + for (; i<48; i+=2){ + if (BitStream[i+1]==BitStream[i+2]) offsetA=0; + if (BitStream[i+2]==BitStream[i+3]) offsetB=0; + } + if (!offsetA && offsetB) offset++; + for (i=offset; i<*size-3; i+=2){ + //check for phase error + if (BitStream[i+1]==BitStream[i+2]) { + BitStream[bitnum++]=7; + errCnt++; + } + if((BitStream[i]==1 && BitStream[i+1]==0) || (BitStream[i]==0 && BitStream[i+1]==1)){ + BitStream[bitnum++]=1^invert; + } else if((BitStream[i]==0 && BitStream[i+1]==0) || (BitStream[i]==1 && BitStream[i+1]==1)){ + BitStream[bitnum++]=invert; + } else { + BitStream[bitnum++]=7; + errCnt++; + } + if(bitnum>MaxBits) break; + } + *size=bitnum; + return errCnt; +} + +// by marshmellow // demod gProxIIDemod // error returns as -x // success returns start position in BitStream @@ -780,12 +633,13 @@ int PyramiddemodFSK(uint8_t *dest, size_t *size) return (int)startIdx; } - -uint8_t DetectCleanAskWave(uint8_t dest[], size_t size, int high, int low) +// by marshmellow +// to detect a wave that has heavily clipped (clean) samples +uint8_t DetectCleanAskWave(uint8_t dest[], size_t size, uint8_t high, uint8_t low) { uint16_t allPeaks=1; uint16_t cntPeaks=0; - size_t loopEnd = 572; + size_t loopEnd = 512+60; if (loopEnd > size) loopEnd = size; for (size_t i=60; ilow && dest[i]128) { - if (!high){ - high=1; - if (cnt > highCnt){ - if (highCnt != 0) highCnt2 = highCnt; - highCnt = cnt; - } else if (cnt > highCnt2) { - highCnt2 = cnt; - } - cnt=1; - } else { - cnt++; - } - } else if (dest[idx] <= 128){ - if (high) { - high=0; - if (cnt > highCnt) { - if (highCnt != 0) highCnt2 = highCnt; - highCnt = cnt; - } else if (cnt > highCnt2) { - highCnt2 = cnt; - } - cnt=1; - } else { - cnt++; - } - } + uint8_t fndClk[] = {8,16,32,40,50,64,128}; + size_t startwave; + size_t i = 0; + size_t minClk = 255; + // get to first full low to prime loop and skip incomplete first pulse + while ((dest[i] < high) && (i < size)) + ++i; + while ((dest[i] > low) && (i < size)) + ++i; + + // loop through all samples + while (i < size) { + // measure from low to low + while ((dest[i] > low) && (i < size)) + ++i; + startwave= i; + while ((dest[i] < high) && (i < size)) + ++i; + while ((dest[i] > low) && (i < size)) + ++i; + //get minimum measured distance + if (i-startwave < minClk && i < size) + minClk = i - startwave; } - uint8_t tol; - for (idx=8; idx>0; idx--){ - tol = clk[idx]/8; - if (clk[idx] >= highCnt - tol && clk[idx] <= highCnt + tol) - return clk[idx]; - if (clk[idx] >= highCnt2 - tol && clk[idx] <= highCnt2 + tol) - return clk[idx]; + // set clock + for (uint8_t clkCnt = 0; clkCnt<7; clkCnt++) { + if (minClk >= fndClk[clkCnt]-(fndClk[clkCnt]/8) && minClk <= fndClk[clkCnt]+1) + return fndClk[clkCnt]; } - return -1; + return 0; } // by marshmellow @@ -856,45 +696,61 @@ int DetectStrongAskClock(uint8_t dest[], size_t size) // return start index of best starting position for that clock and return clock (by reference) int DetectASKClock(uint8_t dest[], size_t size, int *clock, int maxErr) { - size_t i=0; - uint8_t clk[]={8,16,32,40,50,64,100,128,255}; + size_t i=1; + uint8_t clk[] = {255,8,16,32,40,50,64,100,128,255}; + uint8_t clkEnd = 9; uint8_t loopCnt = 255; //don't need to loop through entire array... if (size <= loopCnt) return -1; //not enough samples - //if we already have a valid clock quit - - for (;i<8;++i) - if (clk[i] == *clock) return 0; + + //if we already have a valid clock + uint8_t clockFnd=0; + for (;i0; i--){ - if (clk[i] == ans) { - *clock = ans; - return 0; + if (!clockFnd){ + if (DetectCleanAskWave(dest, size, peak, low)==1){ + int ans = DetectStrongAskClock(dest, size, peak, low); + for (i=clkEnd-1; i>0; i--){ + if (clk[i] == ans) { + *clock = ans; + //clockFnd = i; + return 0; // for strong waves i don't use the 'best start position' yet... + //break; //clock found but continue to find best startpos [not yet] + } } } } + uint8_t ii; uint8_t clkCnt, tol = 0; uint16_t bestErr[]={1000,1000,1000,1000,1000,1000,1000,1000,1000}; uint8_t bestStart[]={0,0,0,0,0,0,0,0,0}; size_t errCnt = 0; size_t arrLoc, loopEnd; + + if (clockFnd>0) { + clkCnt = clockFnd; + clkEnd = clockFnd+1; + } + else clkCnt=1; + //test each valid clock from smallest to greatest to see which lines up - for(clkCnt=0; clkCnt < 8; clkCnt++){ - if (clk[clkCnt] == 32){ + for(; clkCnt < clkEnd; clkCnt++){ + if (clk[clkCnt] <= 32){ tol=1; }else{ tol=0; } - if (!maxErr) loopCnt=clk[clkCnt]*2; + //if no errors allowed - keep start within the first clock + if (!maxErr && size > clk[clkCnt]*2 + tol && clk[clkCnt]<128) loopCnt=clk[clkCnt]*2; bestErr[clkCnt]=1000; - //try lining up the peaks by moving starting point (try first 256) + //try lining up the peaks by moving starting point (try first few clocks) for (ii=0; ii < loopCnt; ii++){ if (dest[ii] < peak && dest[ii] > low) continue; @@ -910,11 +766,11 @@ int DetectASKClock(uint8_t dest[], size_t size, int *clock, int maxErr) errCnt++; } } - //if we found no errors then we can stop here + //if we found no errors then we can stop here and a low clock (common clocks) // this is correct one - return this clock //PrintAndLog("DEBUG: clk %d, err %d, ii %d, i %d",clk[clkCnt],errCnt,ii,i); - if(errCnt==0 && clkCnt<6) { - *clock = clk[clkCnt]; + if(errCnt==0 && clkCnt<7) { + if (!clockFnd) *clock = clk[clkCnt]; return ii; } //if we found errors see if it is lowest so far and save it as best run @@ -924,9 +780,9 @@ int DetectASKClock(uint8_t dest[], size_t size, int *clock, int maxErr) } } } - uint8_t iii=0; + uint8_t iii; uint8_t best=0; - for (iii=0; iii<8; ++iii){ + for (iii=1; iii maxErr) return -1; - *clock = clk[best]; + //if (bestErr[best] > maxErr) return -1; + if (!clockFnd) *clock = clk[best]; return bestStart[best]; } @@ -1115,7 +971,7 @@ void psk1TOpsk2(uint8_t *BitStream, size_t size) size_t i=1; uint8_t lastBit=BitStream[0]; for (; i lastClkBit + *clock + tol + fc){ lastClkBit += *clock; //no phase shift but clock bit