Patent ID: 11888494
Assignee: NUVOTON TECHNOLOGY CORPORATION
Field: Basic communication processes (Electrical engineering)
Classification: CPC H | IPC H

Claim 8:
9. A semiconductor circuit including a data converter that outputs a digital output signal corresponding to a measured signal, the semiconductor circuit comprising:
an analog circuit that quantizes the measured signal inputted; and
a digital circuit that outputs the digital output signal,
wherein the analog circuit includes:
a correction element group including one or more correction elements each for correcting nonlinearity that occurs during a process of converting the measured signal into the digital output signal in the analog circuit; and
a test element group including one or more test elements for testing the one or more correction elements,

the digital circuit tests the correction element group using the test element group,
the digital circuit includes:
a self-diagnostic code generation circuit that generates a self-diagnostic code for (i) enabling or disabling each of the one or more correction elements included in the correction element group and (ii) enabling or disabling each of the one or more test elements included in the test element group;
an error detection circuit that detects, as an error signal, a difference between a quantizer output signal of the analog circuit and a predetermined threshold value, the quantizer output signal being outputted in response to the self-diagnostic code; and
a self-diagnostic circuit that generates a self-diagnostic signal indicating a diagnostic result of the correction element group, based on the error signal,

the digital circuit causes the self-diagnostic circuit to self-diagnose each of the one or more correction elements included in the correction element group,
the data converter includes an input switch that switches a signal to be inputted to the data converter between the measured signal and the reference signal,
the self-diagnostic code generation circuit has an optimum correction code output mode for outputting an optimum correction code so that a quantization error of the quantizer becomes minimum,
at time of testing, the digital circuit:
enters the optimum correction code output mode, selects a first reference signal using the input switch, and calculates the optimum correction code as a first optimum correction code;
enters the optimum correction code output mode, selects a second reference signal using the input switch, and calculates the optimum correction code as a second optimum correction code; and
calculates a difference between the first optimum correction code and the second optimum correction code, and performs a correction range diagnosis on the correction element group.