摘要:
A circuit measures the signal propagation delay through a selected test circuit. The test circuit is provided with an inverting feedback path so that the test circuit and feedback path together form a free-running oscillator. The oscillator then automatically provides its own test signal that includes alternating rising and falling signal transitions on the test-circuit input node. These signal transitions are counted over a predetermined time period to establish the average period of the oscillator. Finally, the average period of the oscillator is related to the average signal propagation delay through the test circuit. One embodiment of the invention includes a phase discriminator that samples the output of the oscillator and accumulates data representing the duty cycle of that signal. The duty cycle can then be combined with the average period of the test signal to determine, separately, the delays associated with falling and rising edges propagating through the test circuit.
摘要:
A circuit measures the signal propagation delay through a selected test circuit. The test circuit is provided with a feedback path so that the test circuit and feedback path together form a free-running oscillator. The oscillator then automatically provides its own test signal that includes alternating rising and falling signal transitions on the test-circuit input node. A phase discriminator samples the output of the oscillator and accumulates data representing the signal propagation delay of either rising or falling signal transitions propagating through the test circuit. The worst-case delay associated with the test circuit can then be expressed as the longer of the two. Knowing the precise worst-case delay allows IC A designers to minimize the guard band and consequently guarantee higher speed performance.
摘要:
A circuit measures the signal propagation delay through a selected test circuit. The test circuit is provided with a feedback path so that the test circuit and feedback path together form a free-running oscillator. The oscillator then automatically provides its own test signal that includes alternating rising and falling signal transitions on the test-circuit input node. A phase discriminator samples the output of the oscillator and accumulates data representing the signal propagation delay of either rising or falling signal transitions propagating through the test circuit. The worst-case delay associated with the test circuit can then be expressed as the longer of the two. Knowing the precise worst-case delay allows IC designers to minimize the guard band and consequently guarantee higher speed performance.
摘要:
A circuit measures the signal propagation delay through a selected test circuit. The test circuit is provided with a feedback path so that the test circuit and feedback path together form a free-running oscillator. The oscillator then automatically provides its own test signal that includes alternating rising and falling signal transitions on the test-circuit input node. These signal transitions are counted over a predetermined time period to establish the average period of the oscillator. Finally, the average period of the oscillator is related to the average signal propagation delay through the test circuit. A phase discriminator samples the output of the oscillator and accumulates data representing the duty cycle of that signal. The duty cycle can then be combined with the average period of the test signal to determine, separately, the delays associated with falling and rising edges propagating through the test circuit.
摘要:
A circuit measures the signal propagation delay through a selected test circuit. The test circuit is provided with a feedback path so that the test circuit and feedback path together form a free-running oscillator. The oscillator then automatically provides its own test signal that includes alternating rising and falling signal transitions on the test-circuit input node. These signal transitions are counted over a predetermined time period to establish the period of the oscillator. The period of the oscillator is then related to the average signal propagation delay through the test circuit. The invention can be applied to synchronous components that might fail to oscillate by connecting the asynchronous set or clear terminal to the output terminal so that the oscillator oscillates at a frequency determined by the clock-to-out delay of those components. The configuration can thus be used to characterize synchronous and asynchronous components to provide data for predicting the timing behavior of circuits that include those or similar components.
摘要:
A circuit measures the signal propagation delay through a selected test circuit. The test circuit is provided with a feedback path so that the test circuit and feedback path together form a free-running oscillator. The oscillator then automatically provides its own test signal that includes alternating rising and falling signal transitions on the test-circuit input node. These signal transitions are counted over a predetermined time period to establish the period of the oscillator. The period of the oscillator is then related to the average signal propagation delay through the test circuit. The invention can be applied to synchronous components that might fail to oscillate by connecting the asynchronous set or clear terminal to the output terminal so that the oscillator oscillates at a frequency determined by the clock-to-out delay of those components. The configuration can thus be used to characterize synchronous and asynchronous components to provide data for predicting the timing behavior of circuits that include those or similar components.
摘要:
A plurality of FPGA dice is disposed upon a semiconductor substrate. In order to supply the immense power required by the plurality of FPGA dice, power is routed through the semiconductor substrate vertically from thick metal layers and large integral metal structures located on the other side of the semiconductor substrate. Because the semiconductor substrate has a different coefficient of thermal linear expansion than metal layers in contact with the substrate, delamination may occur when the structure is subject to changes in temperature. To prevent delamination of metal layers connected to the semiconductor substrate and in electrical contact with the integral metal structures, the integral metal structures are manufactured with an array of post portions. During changes in temperature, the post portions of the integral metal structures bend and slide relative to metal layers connected to the semiconductor substrate and prevent linear stresses that may otherwise cause delamination.
摘要:
Low temperature bond balls connect two structures having disparate coefficients of linear thermal expansion. An integrated circuit is made to heat the device such that the low temperature bond balls melt. After melting, the bond balls solidify, and the device is operated with the bond balls solidified. In one example, one of the two structures is a semiconductor substrate, and the other structure is a printed circuit board. The integrated circuit is a die mounted to the semiconductor substrate. The bond balls include at least five percent indium, and the integrated circuit is an FPGA loaded with a bit stream. The bit stream configures the FPGA such that the FPGA has increased power dissipation, which melts the balls. After the melting, a second bit stream is loaded into the FPGA and the FPGA is operated in a normal user-mode using the second bit stream.
摘要:
An electronic package and methods by which the package reduces thermal fatigue failure of conductors in the electronic package. The electronic package includes a carrier substrate having first and second surfaces and a plurality of anchor vias having a via material extending from the first surface toward the second surface. The electronic package includes a first conducting layer having a length and a width extending laterally in two dimensions across a major part of the first surface of the carrier substrate. The anchor vias have plural attachments along the length and the width of the first conducting layer to secure the first conducting layer to the carrier substrate.
摘要:
A reconfigurable high performance computer occupies less than 360 cubic inches and has an approximate compute power of 0.7 teraflops per second while consuming less than 1000 watts. The computer includes a novel stack of semiconductor substrate assemblies. Some semiconductor substrate assemblies involve field programmable gate array (FPGA) dice that are directly surface mounted, as bare die, to a semiconductor substrate. Other semiconductor substrate assemblies of the stack involve bare memory integrated circuit dice that are directly surface mounted to a semiconductor substrate. Elastomeric connectors interconnect adjacent semiconductor substrates proceeding down the stack. Tines of novel comb-shaped power bus bar assembly structures extend into the stack to supply DC supply voltages. The supply voltages are supplied from bus bars, through vias in the semiconductor substrates, and to the integrated circuits on the other side of the substrates. The power bus bars also serve as capacitors and guides for liquid coolant.