{'fraction_non_alphanumeric': 0.03205128205128205, 'fraction_numerical': 0.016025641025641024, 'mean_word_length': 4.73394495412844, 'pattern_counts': {'":': 0, '<': 0, '<?xml version=': 0, '>': 0, 'https://': 0, 'lorem ipsum': 0, 'www.': 0, 'xml': 0}, 'pii_count': 0, 'substrings_counts': 0, 'word_list_counts': {'cursed_substrings.json': 0, 'profanity_word_list.json': 0, 'sexual_word_list.json': 0, 'zh_pornsignals.json': 0}}
A sine-output ROM-less direct digital frequency synthesiser using a polynomial approximation

This paper describes the design and implementation of a ROM-less sine-output direct digital frequency synthesiser by using a polynomial approximation, which provides a maximum error less than 2e-4 for phase values between 0 to /spl pi//2. The full-period sinewave is generated by using a quadrant-decode technique. This yields a very high spectral purity sinewave output. System-level approximation and experimental results using an FPGA show that the maximum harmonic distortion is less than -67.4 dBc and -64.8 dBc respectively.