Abstract: A test circuit that includes a scan path having serially coupled scan flip-flops clocked by a system clock signal, an index counter clocked by the system clock for providing an index output for tracking data in the scan path, a control circuit clocked by a test clock signal for receiving scan input data from an external source and for providing output data to the external source, an input memory for receiving scan input data from the control circuit, an output memory for receiving the output of the scan path, and a selection circuit having a first input for receiving the output of the scan path, a second input for receiving scan input data from the input memory, and an output connected to the input of the scan path.

Abstract: A boundary scan test circuit that includes Y scan flip-flops serially connected in a sequence from a first scan flip-flop to a Y.sup.th scan flip-flop and clocked with a system clock signal, and circuitry for providing scan input data to the first scan flip-flop synchronously with a test clock signal and for receiving scan output data from the Y.sup.th scan flip-flop synchronously with the test clock signal, wherein the test clock signal and the system clock signal have a test clock period to system clock period ratio that is equal to any fixed integer ratio M.

Abstract: A device and method for removal of debris from well bores coincident with introduction and placement of a bridge plug. The device comprises a hollow cylindrical body open at both ends. The lower end of the device is adapted to form a gauge ring, integral with the body of the device for cleaning or scraping of the well casing. The body of the device is penetrated by a plurality of openings of sufficient size to allow the passage of fluid while confining debris within the body of the device. The upper end of the device is adapted to be frangibly connected to the bottom of the bridge plug to be placed in the well casing. The method includes preparation of a well for production, wherein debris removal and bridge plug placement may be safely and economically performed in a single operation.