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partial eye diagram implementation

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Jan Käberich 2022-10-19 17:31:14 +02:00
parent 9a198217b8
commit c7a99af820
17 changed files with 7404 additions and 25 deletions
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43
Software/PC_Application/LibreVNA-GUI/Util/prbs.cpp Normal file
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#include "prbs.h"
#include <array>
PRBS::PRBS(unsigned int bits)
{
this->bits = bits;
// from https://www.eetimes.com/tutorial-linear-feedback-shift-registers-lfsrs-part-1/
const std::array<unsigned int, 12> polynoms = {{
0x00000000,
0x00000000,
0x00000003,
0x00000005,
0x00000009,
0x00000012,
0x00000021,
0x00000041,
0x0000008E,
0x00000108,
0x00000204,
0x00000402,
}};
if(bits < 2 || bits >= polynoms.size()) {
throw std::runtime_error("Bit size not supported");
}
polynom = polynoms[bits];
shiftReg = 0xFFFFFFFF;
}
bool PRBS::next()
{
bool newbit = false;
unsigned int mask = 0x01;
for(unsigned int i=0;i<bits;i++) {
if(polynom & mask & shiftReg) {
newbit = !newbit;
}
mask <<= 1;
}
shiftReg = (shiftReg << 1) | (newbit ? 0x01 : 0x00);
return newbit;
}