Abstract: Embodiments of a synchronous digital system are disclosed that may include generation of clock and synchronization signals. Any of a plurality of available clock signals may be selected for use as a primary clock, without causing clock-induced errors in the synchronous digital system. A clock signal generated on-chip with the synchronous digital system may be automatically selected in response to detecting a condition indicating that use of a local clock may be necessary. Such conditions may include detection of tampering with the synchronous digital system. If an indication of tampering is detected, security measures may be performed.

Abstract: Embodiments are disclosed of an apparatus capable of performing multi-rate synchronous communication between component chips. Each chip may receive a common clock reference signal, and may generate an internal clock signal dependent on the clock reference signal. A clock distribution tree and phase-locked loop may be used to minimize internal clock skew at I/O circuitry at the chip perimeter. Each chip may also generate an internal synchronizing signal that is phase-aligned to the received clock reference signal. Each chip may use its respective synchronizing signal to synchronize multiple clock dividers that provide software-selectable adjusted-frequency clock signals to the I/O cells of the chip. In this way, the adjusted-frequency clock signals of the multiple chips are edge-aligned to the low-skew internal clock signals, and phase-aligned to the common clock reference signal, allowing the I/O cells of the multiple chips to perform synchronous communication at multiple rates with low clock skew.

Abstract: Embodiments are disclosed of an apparatus capable of performing multi-rate synchronous communication between component chips. Each chip may receive a common clock reference signal, and may generate an internal clock signal dependent on the clock reference signal. A clock distribution tree and phase-locked loop may be used to minimize internal clock skew at I/O circuitry at the chip perimeter. Each chip may also generate an internal synchronizing signal that is phase-aligned to the received clock reference signal. Each chip may use its respective synchronizing signal to synchronize multiple clock dividers that provide software-selectable adjusted-frequency clock signals to the I/O cells of the chip. In this way, the adjusted-frequency clock signals of the multiple chips are edge-aligned to the low-skew internal clock signals, and phase-aligned to the common clock reference signal, allowing the I/O cells of the multiple chips to perform synchronous communication at multiple rates with low clock skew.

Abstract: Embodiments are disclosed of a multi-chip apparatus capable of performing multi-rate synchronous communication between component chips. Each chip may receive a common clock reference signal, and may generate an internal clock signal dependent on the clock reference signal. A clock distribution tree and phase-locked loop may be used to minimize internal clock skew at I/O circuitry at the chip perimeter. Each chip may also generate an internal synchronizing signal that is phase-aligned to the received clock reference signal. Each chip may use its respective synchronizing signal to synchronize multiple clock dividers that provide software-selectable reduced-frequency clock signals to the I/O cells of the chip. In this way, the reduced-frequency clock signals of the multiple chips are edge-aligned to the low-skew internal clock signals, and phase-aligned to the common clock reference signal, allowing the I/O cells of the multiple chips to perform synchronous communication at multiple rates with low clock skew.

Abstract: Various embodiments are disclosed of a multiprocessor system with processing elements optimized for high performance and low power dissipation and an associated method of programming the processing elements. Each processing element may comprise a fetch unit and a plurality of address generator units and a plurality of pipelined datapaths. The fetch unit may be configured to receive a multi-part instruction, wherein the multi-part instruction includes a plurality of fields. A first address generator unit may be configured to perform an arithmetic operation dependent upon a first field of the plurality of fields. A second address generator unit may be configured to generate at least one address of a plurality of addresses, wherein each address is dependent upon a respective field of the plurality of fields. A parallel assembly language may be used to control the plurality of address generator units and the plurality of pipelined datapaths.

Abstract: Embodiments of a synchronous digital system are disclosed that may include generation of clock and synchronization signals. Any of a plurality of available clock signals may be selected for use as a primary clock, without causing clock-induced errors in the synchronous digital system. A clock signal generated on-chip with the synchronous digital system may be automatically selected in response to detecting a condition indicating that use of a local clock may be necessary. Such conditions may include detection of tampering with the synchronous digital system. If an indication of tampering is detected, security measures may be performed.

Abstract: Embodiments are disclosed of a multi-chip apparatus capable of performing multi-rate synchronous communication between component chips. Each chip may receive a common clock reference signal, and may generate an internal clock signal dependent on the clock reference signal. A clock distribution tree and phase-locked loop may be used to minimize internal clock skew at I/O circuitry at the chip perimeter. Each chip may also generate an internal synchronizing signal that is phase-aligned to the received clock reference signal. Each chip may use its respective synchronizing signal to synchronize multiple clock dividers that provide software-selectable reduced-frequency clock signals to the I/O cells of the chip. In this way, the reduced-frequency clock signals of the multiple chips are edge-aligned to the low-skew internal clock signals, and phase-aligned to the common clock reference signal, allowing the I/O cells of the multiple chips to perform synchronous communication at multiple rates with low clock skew.

Abstract: Embodiments of a synchronous digital system are disclosed that may include generation of clock and synchronization signals. Any of a plurality of available clock signals may be selected for use as a primary clock, without causing clock-induced errors in the synchronous digital system. The clock signals may be selected automatically or programmatically. Clock generation circuitry may generate a clock signal that is initially used as the primary clock. The clock generation circuitry may be dynamically reconfigured without interrupting operation of the synchronous digital system, by first selecting another of the available clock signals for use as the primary clock.

Abstract: Embodiments of a multi-processor array are disclosed that may include a plurality of processors, and controllers. Each processor may include a plurality of processor ports and a sync adapter. Each sync adapter may include a plurality of adapter ports. Each controller may include a plurality of controller ports, and a configuration port. The plurality of processors and the plurality of controllers may be coupled together in an interspersed arrangement, and the controllers may be distinct from the processors. Each processor may be configured to send a synchronization signal through its adapter ports to one or more controllers, and to pause execution of program instructions while waiting for a response from the one or more controllers.