27 lines
1.5 KiB
Python
27 lines
1.5 KiB
Python
import numpy as np
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TRNG_PAIR_CNT = 64
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if __name__ == '__main__':
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# reading info file - length of trace, sampling frequency (not necessary to know in our case), random value generated by the TRNG
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with open("data_info.txt", "r") as fin:
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tracelen = int(fin.readline())
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fs = int(fin.readline())
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trng_val = fin.readline()
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traces = np.fromfile("data.bin", dtype='uint8') # reading traces for individual ROs
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traces = np.reshape(traces, (traces.size//tracelen, tracelen)) # reshape of matrix, each row contains the trace for one RO
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traces_bin = traces > 128 # conversion of waveforms to rectangles - everything below threshold is 0, otherwise 1 (they are boolean values actually)
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rising_edges = np.logical_not(traces_bin[:,0:-2]) & np.logical_not(traces_bin[:,1:-1]) & traces_bin[:,2:] # finding rising edges, each rising edge is represented by True
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cnt = np.count_nonzero(rising_edges, axis=1) # count the number of rising edges in rows
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# cnt is now a 1D vector
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cnt = cnt.reshape(TRNG_PAIR_CNT,2).min(axis=1) # Reshape of the count array into matrix, where each row contains 2 values - the number of rising edges for two ROs in a pair. Then we select the smaller value.
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cnt_sel = cnt & 0x03 # select only the two least significant bits
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estimate = ''.join([np.binary_repr(x, width=2) for x in cnt_sel]) # binary representation of the values (the last 2 bits) and joining them into one string
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print('{0:0>32x}'.format(int(estimate, 2)))
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print(trng_val) # from data_info, output of the RNG in FPGA
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