Multiplexer circuit and method for detection of the switching state of switching elements
AssigneeSiemens Aktiengesellschaft
InventorHubert Limbrunner
Life of this patent
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Abstract
Multiplexer circuit having a number of signal inputs (4.1-4.6) for receiving in each case one input signal, at least one signal output (IN1-IN3) for outputting an output signal which corresponds to one of the input signals, at least one control input (STROBE1, STROBE2) for receiving a control signal which selects at least one of the input signals for passing on to the signal output, a sampling circuit (T1-T4, R16-R23) which is connected to the signal inputs (4.1-4.6), for sampling the signal inputs (4.1-4.6) with a sampling signal with the sampling circuit being connected to the control input (STROBE1, STROBE2), and applying the sampling signal to a single signal input or to a group of signal inputs as a function of the control signal.
Claims20
A multiplexer circuit for detection of the switching state of a number of switching elements by means of a microprocessor in a motor vehicle, comprising
- a number of signal inputs for receiving in each case one input signal,
- at least one signal output for outputting an output signal which corresponds to one of the input signals,
- at least one control input for receiving a control signal which selects at least one of the input signals for passing on to the at least one signal output,
- a sampling circuit which is connected to the signal inputs-, for sampling the signal inputs with a sampling signal in order to check the electrical state of the switching elements which are connected to the signal inputs with the sampling circuit being connected to the control input, wherein
- the sampling circuit applies the sampling signal to a group of signal inputs as a function of the control signal, and
- a number of signal inputs are jointly connected to said at least one signal output wherein only one of the jointly connected signal inputs is assigned to said group.
A multiplexer circuit in a microprocessor arrangement, comprising:
- a number of signal outputs,
- a number of switching elements each connected to a respective signal input wherein said signal inputs are coupled through a connecting network with the number of signal outputs, wherein the number of switching elements is higher than the number of signal outputs and wherein the connecting network couples at least two switching elements with one signal output;
- a sampling circuit having at least one control input for generating a sampling signal which depending on a control signal feeds a bias signal to the signal inputs of a predefined group of the switching elements wherein only one switching element of the at least two switching elements receives the bias signal.
Method for operating a microprocessor arrangement for determining the status of a plurality of switching elements, wherein the microprocessor comprises a plurality of signal inputs being less than the plurality of switching elements, the method comprising the steps of:
- coupling the plurality of switching elements through a connecting network with the plurality of microprocessor inputs, wherein at least two switching elements are coupled with one microprocessor input;
- generating a sampling signal which is fed to a predefined group of the switching elements wherein said group includes only one of said at least two switching elements.
Dependencies are inferred from the claim text.