Patent ID: 7512856
Filing Date: 2009-03-31
Classification: G01R

Abstract:
1. A register circuit, comprising: a latch circuit, for latching an input data to generate an output data; an input signal selecting circuit, coupled to a non-test data and a test data respectively, for selectively outputting the non-test data or the test data as the input data; a control circuit, coupled to a driving clock, for controlling the latch circuit to selectively latch the input data for determining the output data according to the driving clock; and a scanning circuit, coupled to the driving clock and the latch circuit, for scanning the output data of the latch circuit to generate a scanning data according to the driving clock; wherein when the driving clock has a transition from a first logical level to a second logical level, the control circuit allows the latch circuit to latch the input data for determining the output data, and the scanning circuit scans the output data to generate the scanning data; and when the driving clock has a transition from the second logical level to the first logical level, the control circuit does not allow the latch circuit to latch the input data for determining the output data, and the scanning circuit holds the scanning data.