Patent ID: 7850086

Claim:
A semiconductor integrated circuit, to which a power supply voltage is supplied via electromagnetic waves received by an antenna coil, and which exchanges data via the antenna coil, the semiconductor integrated circuit comprising: a memory circuit storing data; a pair of terminals to which the antenna coil is connected; a modulating-transmitting circuit for transmitting data via the antenna coil by varying a load between the terminals according to data to be transmitted; a transmission control circuit for outputting data stored in the memory circuit to the modulating-transmitting circuit; and a reset signal generating circuit for outputting a reset signal for resetting the transmission control circuit to the transmission control circuit when the power supply voltage decreases below a predetermined threshold value, wherein: the transmission control circuit is configured to output a transmission status signal, which indicates that data is being transmitted; and the reset signal generating circuit is configured so that the threshold value is lower during a period in which the transmission status signal is being output than during a period in which the transmission status signal is not being output.