Communications system and memory card

A communications system comprising a transponder having no radio wave generating source executes data transmission with a reader/writer, wherein

• said transponder is incorporated in a memory card having a memory with which said reader/writer reads and writes information, said memory card being used as loaded in a dedicated slot of a host device;
• said reader/writer transmits a beacon signal telling a service area of said reader/writer at a predetermined time interval;
• and
• said memory card has rectifying means for obtaining a direct-current voltage by rectifying a signal received from said reader/writer, is normally in a sleep state in which at least a wait state by said transponder is stopped, and returns from said sleep state by use of said direct-current voltage obtained by said rectifying means as a startup interrupt signal, executing a beacon signal waiting by said transponder.

A memory card to be used on a host device as loaded in a dedicated slot thereof, comprising:

• storage means for storing data;
• a terminal block configured to connect said memory card with said host device through said dedicated slot;
• a radio block configured to operate as a transponder in a communications system in which a transponder having no radio wave generating source executes data transmission with a reader/writer;
• a control block configured to control access by said terminal block and said radio block to said storage means;
• and
• a timer configured to provide waiting for a signal from said reader/writer for a preset period of time,
• wherein said memory, card starts up said timer in response to detection, through said terminal block, of power-on of said host device, executes a connection establishment procedure with said reader/writer in response to reception of a beacon signal from said reader/writer before said timer expires, and, if said timer expires before a beacon signal is received, gets in a sleep state in which at least a wait state of said radio block is stopped.

A memory card to be used on a host device as loaded in a dedicated slot, comprising:

• storage means for storing data;
• a terminal block configured to connect said memory card with said host device through said dedicated slot;
• a radio block configured to operate as a transponder in a communications system in which a transponder having no radio wave generating source executes data transmission with a reader/writer;
• a control block configured to control access by said terminal block and said radio block to said storage means, and
• rectifying means for rectifying a signal received from said reader/writer into a direct-current voltage,
• wherein said memory card is normally in a sleep state in which at least a wait state of said radio block is stopped, returns from said sleep state by use of a direct-current voltage obtained by said rectifying, means as a startup interrupt signal, and waits for a beacon signal from said reader/writer.