Code system conversion circuit for converting binary-coded decimal (BCD) codes to Lee restrict competition count codes

The invention discloses a code system conversion circuit for converting binary-coded decimal (BCD) codes to Lee restrict competition count codes, which comprises an input register, a decoding logic circuit and an output register, wherein the input end of the input register is used for inputting BCD codes to be converted and inputting the BCD codes to be converted into the decoding logic circuit after the BCD codes to be converted are synchronized through synchronous clock signals; the decoding logic circuit decodes the synchronized BCD codes and then sends the synchronized BCD codes to the output register; and the output register is further connected with the synchronous clock signals and outputs four-bit Lee codes under control of the synchronous clock signals, and the output register is further connected with reset signals capable of resetting the circuit. The code system conversion circuit for converting the BCD codes to the Lee restrict competition count codes can achieve reset control and convert the input BCD codes to the Lee codes fast and accurately.