Passive contactless integrated circuit comprising a flag for monitoring an erase/programming voltage
AssigneeSTMicroelectronics S.r.l.
InventorsDavid Naura, Christophe Moreaux, Ahmed Kari, Pierre Rizzo
Life of this patent
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Abstract
A passive contactless integrated circuit includes an electrically programmable non-volatile data memory (MEM), a charge accumulation booster circuit for supplying a high voltage necessary for writing data in the memory. The integrated circuit includes a volatile memory point for memorizing an indicator flag, and circuitry for modifying the value of the indicator flag when the high voltage reaches a critical threshold for the first time after activating the booster circuit.
Claims25
A passive contactless integrated circuit, comprising:
- an electrically programmable non-volatile data memory;
- a charge accumulation booster circuit to supply a high voltage sufficient to write data in the memory;
- a volatile memory cell to store an indicator flag;
- means for modifying the indicator flag when the high voltage reaches a threshold for a first time after activating the booster circuit;
- and
- a switch circuit coupled between the charge accumulation booster circuit and the non-volatile data memory to apply the high voltage to the non-volatile data memory as long as the high voltage has reached the threshold at least once after activating the charge accumulation booster circuits.
A portable electronic object, comprising:
- a portable support and an integrated circuit carried thereby, the integrated circuit including an electrically programmable non-volatile data memory;
- a charge accumulation booster circuit coupled to said memory to supply a high voltage sufficient to write data in the memory;
- a volatile memory cell to store an indicator flag;
- circuitry to modify the indicator flag when the high voltage reaches a threshold for a first time after activation of the booster circuit;
- and
- a switch circuit coupled between the charge accumulation booster circuit and the non-volatile data memory to apply the high voltage to the non-volatile data memory as long as the high voltage has reached the threshold at least once after activating the charge accumulation booster circuit.
A method for writing a datum in an electrically programmable non-volatile memory of a passive contactless integrated circuit, the method comprising:
- initializing an indicator flag in a volatile memory cell of the integrated circuit;
- activating a charge accumulation booster circuit supplying a high voltage sufficient to write the datum in the memory;
- changing the indicator flag if the high voltage reaches a threshold for a first time after activating the booster circuit;
- and
- activating a switch circuit coupled between the charge accumulation booster circuit and the non-volatile memory to apply the high voltage to the non-volatile memory as long as the high voltage has reached the threshold at least once after activating the booster circuit.
Dependencies are inferred from the claim text.