Decoder suitable for PIE coding

A decoder suitable for PIE coding relates to the technical field of RFID (radio frequency identification). The utility model includes a Cnt-RTcal counter, a Cnt-even counter, a Cnt-odd counter, a Cnt-ctrl counter, a Mux, a comparer and three D triggers. The Cnt-RTcal counter counts the duration of forward link calibrated code RTcal, and the Cnt-ctrl counter counts the number of falling edges in PIE coding data frames received by a tag. The Cnt-ctrl counter counts and outputs Cnt-ctrl to control the Cnt-odd counter and the Cnt-even counter, so as to alternately count the signal width between two adjacent falling edges of the PIE coding data. The utility model can overcome the influences on clock shake and frequency arising from temperature, voltage and the like, ensures the stable and synchronous reception of PIE code, reduces the power consumption of a PIE coding processing circuit, and has the characteristics of small volume, economy, simplification and convenience.