+int DemodPCF7931(uint8_t **outBlocks);
+int IsBlock0PCF7931(uint8_t *Block);
+int IsBlock1PCF7931(uint8_t *Block);
+void ReadPCF7931();
+void EM4xReadWord(uint8_t Address, uint32_t Pwd, uint8_t PwdMode);
+void EM4xWriteWord(uint32_t Data, uint8_t Address, uint32_t Pwd, uint8_t PwdMode);