Method for selectively enabling alternative circuits
AssigneeSTMicroelectronics S.r.l.
InventorLuigi Pascucci
Life of this patent
Estimating the term…
Abstract
A circuit for selectively enabling one circuit from among a plurality of circuit alternatives of an integrated circuit, comprising selection circuit means for selecting one among said circuit alternatives. The selection means are controlled by bistable circuit means having a preferred state. Disactivatable forcing means associated to said bistable means are provided for forcing said bistable means in a state opposite than said preferred state, so that when said forcing means are disactivated the bistable circuit means automatically switch to said preferred state.
Claims4
A method for selectively enabling one of at least first and second circuit alternatives of an integrated circuit by means of selection circuit means controlled by a bistable circuit means, the selection circuit means having first and second states, the first and second states associated with the first and a second circuit alternatives, respectively, the first state being a preferred state, the method comprising the following steps:
- providing the bistable circuit means with two circuit branches, a first circuit branch comprising a first and a second transistor, a second circuit branch comprising a third and a fourth transistor;
- providing said first and fourth transistors with a turn-on voltage lower, in absolute value, than the turn-on voltage of the second and third transistors;
- testing the first circuit alternative;
- placing the bistable circuit means in the second state;
- testing the second circuit alternative;
- choosing between the first and second alternatives;
- and
- placing the bistable circuit means in the first or second state according to the chosen alternative.
A method for selectively enabling one of at least first and second circuit alternatives of an integrated circuit by means of a selection circuit controlled by a bistable circuit, the selection circuit having first and second states, the first and second states associated with first and second circuit alternatives, respectively, the first state being a preferred state, and the bistable circuit having at least two circuit branches, a first branch comprising first and second transistors, and a second branch comprising third and fourth transistors, the method comprising:
- providing the first and fourth transistors with a turn-on voltage lower, in absolute value, than the turn-on voltage of the second and third transistors;
- testing the first circuit alternative;
- placing the bistable circuit in the second state;
- testing the second circuit alternative;
- choosing between the first and second circuit alternatives;
- and
- placing the bistable circuit in the first or second state according to the chosen alternative.
Dependencies are inferred from the claim text.