Abstract: A circuit and corresponding method enable glitch-free frequency. The circuit comprises a first delay circuit and a second delay circuit, configured to produce first and second propagated enables, respectively, from first and second input enables, respectively; and an output clock circuit. The output clock circuit is configured to produce an output clock that switches, glitch-free, between a first phase-locked clock and a second phase-locked. The first and second delay circuits are further configured to enable the output clock to be switched, glitch-free, by employing the second propagated enable to gate propagation of the first input enable and the first propagated enable to gate propagation of the second input enable, respectively. The first and second input enables are configured to be enabled, alternately, causing the output clock to switch between the first and second phase-locked clocks.

Abstract: Generating a clock signal includes: at a root node of a clock distribution network, receiving a first clock signal; at a first leaf node of the clock distribution network, detecting a reference event and generating a synchronizing signal based on the detection of the reference event; passing the synchronizing signal along a synchronizing signal path from the first leaf node to the root node via one or more clocked storage cells, each storage cell being clocked from a corresponding point within the clock distribution network; at the root node, generating a second clock signal from the first clock signal synchronized to the synchronizing signal received at the root node, and distributing the second clock signal to the leaf nodes of the clock distribution network, the generating of the second clock signal resulting in the second clock signal received at the first leaf node being synchronized to the detected reference event.

Abstract: Generating a clock signal includes: at a root node of a clock distribution network, receiving a first clock signal generated based on a reference clock signal; at a first leaf node, detecting a reference event associated with the reference clock signal and generating a synchronizing signal; passing the synchronizing signal from the first leaf node to the root node; at the root node, generating a second clock signal from the first clock signal synchronized to the synchronizing signal, and distributing the second clock signal to the leaf nodes. Generating the second clock signal includes selecting a repeating pattern of cycles of the first clock signal including fewer than all of the cycles of the first clock signal, and at least every cycle of the first clock signal that is shifted in time by a propagation delay with respect to a rising edge of the reference clock signal.

Abstract: Generating a clock signal includes: at a root node of a clock distribution network, receiving a first clock signal generated based on a reference clock signal; at a first leaf node, detecting a reference event associated with the reference clock signal and generating a synchronizing signal; passing the synchronizing signal from the first leaf node to the root node; at the root node, generating a second clock signal from the first clock signal synchronized to the synchronizing signal, and distributing the second clock signal to the leaf nodes. Generating the second clock signal includes selecting a repeating pattern of cycles of the first clock signal including fewer than all of the cycles of the first clock signal, and at least every cycle of the first clock signal that is shifted in time by a propagation delay with respect to a rising edge of the reference clock signal.

Abstract: Generating a clock signal includes: at a root node of a clock distribution network, receiving a first clock signal; at a first leaf node of the clock distribution network, detecting a reference event and generating a synchronizing signal based on the detection of the reference event; passing the synchronizing signal along a synchronizing signal path from the first leaf node to the root node via one or more clocked storage cells, each storage cell being clocked from a corresponding point within the clock distribution network; at the root node, generating a second clock signal from the first clock signal synchronized to the synchronizing signal received at the root node, and distributing the second clock signal to the leaf nodes of the clock distribution network, the generating of the second clock signal resulting in the second clock signal received at the first leaf node being synchronized to the detected reference event.

Abstract: According to at least one example embodiment, a method of data coherence is employed within a multi-chip system to enforce cache coherence between chip devices of the multi-node system. According at least one example embodiment, a message is received by a first chip device of the multiple chip devices from a second chip device of the multiple chip devices. The message triggers invalidation of one or more copies, if any, of a data block. The data block stored in a memory attached to, or residing in, the first chip device. Upon determining that one or more remote copies of the data block are stored in one or more other chip devices, other than the first chip device, the first chip device sends one or more invalidation requests to the one or more other chip devices for invalidating the one or more remote copies of the data block.