The disclosure describes a novel method and apparatus for improving silicon interposers to include test circuitry for testing stacked die mounted on the interposer. The improvement allows for the stacked die to be selectively tested by an external tester or by the test circuitry included in the interposer.

According to an embodiment, a first aspect relates to a method for testing a scan chain. The method includes segmenting the scan chain into two or more segments; adding a respective multiplexer at end points of each segment, wherein each pair of sequential segment shares a common multiplexer in between; asserting a select signal at a select terminal of the multiplexers such that a relative position of the two or more segments is rearranged positionally in a rearranged scan chain; generating a test pattern to be communicated to an input terminal of the rearranged scan chain and observing a test result at an output of the rearranged scan chain; and determining a fault condition in the rearranged scan chain based on comparing the test result and an expected result.

The disclosure describes a novel method and apparatus for improving silicon interposers to include test circuitry for testing stacked die mounted on the interposer. The improvement allows for the stacked die to be selectively tested by an external tester or by the test circuitry included in the interposer.

An integrated circuit is configured to receive a test clock input and includes circuitry configured to generate test clocks from the test clock input, and test circuitry configured to use the test clocks in a test mode.

A network equipment test device provides a user interface for user specification of a test traffic source, a test traffic destination, SUT and waypoint topology and one or more test cases. In response to receiving the specified input from the user via the interface, the test traffic source is automatically configured to send the test traffic to the destination via the SUT. The waypoint is automatically configured to measure the test traffic. When the test is initiated, test traffic is sent from the test traffic source to the test traffic destination via the SUT and the at least one waypoint. Test traffic is measured at the waypoint, and traffic measurement results are displayed on a visual map of SUT topology.

The disclosure describes a novel method and apparatus for testing different types of TSVs in a single die or different types of TSV connections in a stack of die. The testing is facilitated by test circuitry associated with each type of TSV. The test circuitry includes a scan cell adapted for testing TSVs.

A system comprises a plurality of components, scan chain selection logic coupled to the components, and override selection logic coupled to the scan chain selection logic. The scan chain selection logic selects various of the components to be members of a scan chain under the direction of a host computer. The override selection logic detects a change in the scan chain and, as a result, blocks the entire scan chain from progressing.

Topology discovery of a target system having a plurality of components coupled with a scan topology may be performed by driving a low logic value on the data input signal and a data output signal of the scan topology. An input data value and an output data value for each of the plurality of components is sampled and recorded. A low logic value is then scanned through the scan path and recorded at each component. The scan topology may be determined based on the recorded data values and the recorded scan values.

Control events may be signaled to a target system having a plurality of components coupled to a scan path by using the clock and data signals of the scan path. While the clock signal is held a high logic level, two or more edge transitions are detected on the data signal. The number of edge transitions on the data signal is counted while the clock signal is held at the high logic state. A control event is determined based on the counted number of edge transitions on the data signal after the clock signal transitions to the low logic state.

According to an embodiment, a digital circuit with N number of redundant flip-flops is provided, each having a data input coupled to a common data signal. The digital circuit operates in a functional mode and a test mode. During test mode, a first flip-flop is arranged as part of a test path and N1 flip-flops are arranged as shadow logic. A test pattern at the common data signal is provided and a test output signal is observed at an output terminal of the first flip-flop to determine faults within a test path of the first flip-flop. At the same cycle, the test output signals of each of the N1 number of redundant flip-flops is observed through the functional path to determine faults.