Patent ID: 7308635

Claim:
An electronic circuit comprising: a plurality of configurable cells; a control circuit, the electronic circuit being adapted to working in a standard mode of operation or in a test mode during which the control circuit is active and configures the plurality of configurable cells in any one of the following two states: a functional state in which all of the plurality of configurable cells are functionally linked to logic cells with which they co-operate to form a logic circuit, and a chained state in which all of the plurality of configurable cells are functionally connected in a chain to form a shift register; and a validation circuit in order to perform the following operations successively when the validation circuit receives an instruction for changing the mode of operation of the electronic circuit: produce initialization signals to command the initialization of the plurality of configurable cells, verify, by using data output signals from configurable cells, that all of the plurality of configurable cells have been correctly initialized, and then produce the mode-changing signal only if all of the plurality of configurable cells have been correctly initialized.