Patent ID: 7583180

Claim:
A semiconductor device for a tag included in a communication system, the communication system including the tag and a reader/writer communicating by a radio signal with the tag, the communication system executing a verify process that the reader/writer reads from the tag a write data to determine whether a write operation is correct or not after the reader/writer writes in the tag the write data, the semiconductor device comprising: a supply voltage generator responsive to the radio signal, to generate a supply voltage therefrom; a control unit being operable on the supply voltage of a first voltage value or more, executing a command included in the radio signal; a memory coupled to the control unit and responsive to a memory control signal therefrom, to receive or supply data to be stored or stored therein; a booster boosting the supply voltage more than a second voltage value that is larger than the first voltage value, to generate a write voltage required for writing to the memory during a write cycle, the booster boosting the supply voltage less than the second voltage value to generate a write voltage and being insufficient for writing to the memory during the write cycle; and a detector detecting whether the supply voltage generated by the supply voltage generator is smaller than the second voltage value, wherein the control unit does not execute a transmission process corresponding to a read operation in the verify process in response to the supply voltage being smaller than the second voltage value.