An integrated circuit for on-chip speed grading comprises test circuitry comprising scan chains and a test controller; and wide-range clock signal generation circuitry comprising phase-locked loop circuitry and frequency divider circuitry. The wide-range clock signal generation circuitry is configured to generate a wide-range test clock signal for the test circuitry to conduct a structural delay test for on-chip speed grading. The wide-range test clock signal is generated based on a test clock signal associated with the test circuitry, a frequency range selection signal and a frequency setting signal.

According to one embodiment, a semiconductor device includes: a first scan chain and a second scan chain each including a plurality of cascaded flip-flops; a plurality of power supply lines that supply a power supply voltage to the first and second scan chains, extend in a first direction, and are arranged in a second direction intersecting with the first direction; and a clock control circuit that supplies a first clock to the first scan chain and a second clock to the second scan chain, the second clock having timing different to that of the first clock. The plurality of flip-flops are arranged along the second direction.

Disclosed is a semiconductor integrated circuit including a logic circuit, and a plurality of scan flip-flop circuits that hold input data or output data of the logic circuit and are capable of forming a scan chain for executing a scan test of the logic circuit. Each scan flip-flop circuit includes a scan data input part that receives input of scan data for the scan test, a normal data input part that receives input of normal data different from the scan data, and a data holding part capable of separately holding the normal data and the scan data.

One example includes a clock receiver system. The system includes a scan clock generator configured to receive a shift clock signal and a high-speed clock signal and to generate a scan clock signal for a transition fault test (TFT) based on the high-speed clock signal. The scan clock generator can provide the scan clock signal as having a pulse sequence comprising at least one preliminary pulse followed by periodic logic state transitions in a capture window during the TFT. The system also includes receiver logic configured to receive the scan clock signal and being programmed to identify each of the at least one preliminary pulse and the periodic logic state transitions in the capture window to pass the TFT.

A clock gating cell (CGC) is provided. The clock gating cell includes two latches that can be configured as a flip-flop to use positive/negative edges of a first clock signal to store a value of an input terminal, and the clock gating cell also includes a selector used for the flip-flop to select from values of different input terminals for storing. In addition, in a non-scan testing mode, the clock gating cell can forcefully close an unused latch through an independent signal, and in a scan shift duration and a scan capture duration of a scan testing mode, the clock gating cell can further forcefully output the first clock signal as the gating clock signal according to two independent signals.

A scan test device includes a scan flip flop circuit and a clock gating circuit. The scan flip flop circuit is configured to receive a scan input signal according to a scan clock signal, and to output the received scan input signal to be a test signal. The clock gating circuit is configured to selectively mask the scan clock signal according to a predetermined bit of the test signal and a scan enable signal, in order to generate a test scan clock signal for testing at least one core circuit.

A semiconductor device of the embodiment includes a plurality of scan chains, a shift clock control circuit, and a shift clock generation circuit. The plurality of scan chains each include a plurality of scan flip-flops. The shift clock control circuit outputs, to each of the plurality of scan chains, a control signal that non-inverts or inverts a scan clock signal. The shift clock generation circuit is provided to each of the plurality of scan flip-flops and generates a non-inverted scan clock signal or an inverted scan clock signal based on the control signal, the non-inverted scan clock signal being obtained by non-inverting the scan clock signal, the inverted scan clock signal being obtained by inverting the scan clock signal.

Scan cells of a set of scan chains may be partitioned into at least two control groups of scan cells and at least two observe groups of scan cells. Adjacent scan cells in the set of scan chains may belong to different control groups. Each observe group may include at most one scan cell from each control group, and each control group may include at most one scan cell from each observe group. The control groups and observe groups may be used to perform defect localization on the set of scan chains.

The disclosure describes a novel method and apparatus for improving the operation of a TAP architecture in a device through the use of Command signal inputs to the TAP architecture. In response to a Command signal input, the TAP architecture can perform streamlined and uninterrupted Update, Capture and Shift operation cycles to a target circuit in the device or streamlined and uninterrupted capture and shift operation cycles to a target circuit in the device. The Command signals can be input to the TAP architecture via the devices dedicated TMS or TDI inputs or via a separate CMD input to the device.

A clock self-testing method and circuit. The clock self-testing method includes introducing a first clock signal and a second clock signal, counting cycles of the first clock signal and the second clock signal respectively beginning at the same moment, and if one of the number of cycles of the first clock signal being counted and the number of cycles of the second clock signal being counted is equal to N, determining whether the remained number of cycles is in a count range from M to N. If the remained number of cycles is out of the count range from M to N, the first clock signal and the second clock signal have errors.