Method for demonstrating the dependence of a signal based on another signal
AssigneeBull SAS
InventorsFlorence Akli, Alain Debreil, Christian Niquet
Life of this patent
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Abstract
In order to test whether a given signal of a complex circuit has the correct behavior, a method is provided which makes it possible to obtain in a computer memory a profile of states of other signals. In order to minimize the processing time and the memory space required to obtain this profile, the method uses two binary decision diagrams starting with a binary variable of said one signal, each with two binary decision subdiagrams. The method combines the binary decision subdiagrams so that the given signal is in a first state when the binary variable is at a first value and is not in this first logical state when the binary variable is at a second value.
Claims10
A method for indicating, in connection with a physical element generating a first signal as a function of a second signal and a plurality of third signals, a combination of states of said third signals such that a state change of said second signal changes said first signal from a binary state to a nonbinary state, wherein two binary decision diagrams are associated with said first signal, and wherein
- a first binary decision diagram includes a first binary decision subdiagram that encodes a first set of the combinations of binary states of the third signals for which the first signal is in a first binary state or in a second binary state when the second signal is in the first binary state, and a second binary decision subdiagram that encodes a second set of the combinations of binary states of the third signals for which the first signal is in the first binary state or in the second binary state when the second signal is in the second binary state, and
- a second binary decision diagram includes a third binary decision subdiagram that encodes a third set of the combinations of binary states of the third signals for which the first signal is in the second binary state or in a first nonbinary state when the second signal is in the first binary state and a fourth binary decision subdiagram that encodes a fourth set of the combinations of binary states of the third signals for which the first signal is in the second binary state or in the first nonbinary state when the second signal is in the second binary state said method comprising:
- a first step that includes forming a first logical combination of the first, second and fourth binary decision subdiagrams, in order to generate a fifth binary decision subdiagram that encodes a fifth set of combinations of states of said third signals, for which
- the first signal is in a first binary state or a second binary state when the second signal is in the first binary state,
- the first signal is not in the first binary state or the second binary state when the second signal is in the second binary state, and
- the first signal is in the second binary state or in the first nonbinary state when the second signal is in the second binary state, so that a change of said second signal, viewed as a control signal with reverse polarity, from the second binary state to the first binary state changes said first signal from a binary state to the first nonbinary state.
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