Embodiments of the present invention relate to an architecture that uses hierarchical statistically multiplexed counters to extend counter life by orders of magnitude. Each level includes statistically multiplexed counters. The statistically multiplexed counters includes P base counters and S subcounters, wherein the S subcounters are dynamically concatenated with the P base counters. When a row overflow in a level occurs, counters in a next level above are used to extend counter life. The hierarchical statistically multiplexed counters can be used with an overflow FIFO to further extend counter life.

A technology related to an electronic circuit, specifically, a phase locked loop or a frequency synthesizing apparatus, is disclosed. The frequency synthesizing apparatus includes an injection locked frequency divider and a replica frequency divider having the same circuit configuration as the injection locked frequency divider. A control value required for self-oscillating at a target frequency using the replica frequency divider is determined. When the injection locked frequency divider fails injection locking on a first attempt, the injection locking may be attempted using the determined control value. On the first attempt, the control value of the injection locked frequency divider may be determined and stored in advance according to a temperature and a supply voltage.

A technology related to an electronic circuit, specifically, a phase locked loop or a frequency synthesizing apparatus, is disclosed. The frequency synthesizing apparatus includes an injection locked frequency divider and a replica frequency divider having the same circuit configuration as the injection locked frequency divider. A control value required for self-oscillating at a target frequency using the replica frequency divider is determined. When the injection locked frequency divider fails injection locking on a first attempt, the injection locking may be attempted using the determined control value. On the first attempt, the control value of the injection locked frequency divider may be determined and stored in advance according to a temperature and a supply voltage.

The present invention relates to data communication and electrical circuits. More specifically, embodiments of the present invention provide a clock and data recovery (CDR) architecture implementation for high data rate wireline communication links. In an embodiment, a CDR device includes a phase detector, a loop filter, and a fractional-N PLL. The fractional-N PLL generates output clock signal based on output of the loop filter. There are other embodiments as well.

A queuing requester for access to a memory system is provided. Transaction requests are received from two or more requestors for access to the memory system. Each transaction request includes an associated priority value. A request queue of the received transaction requests is formed in the queuing requester. Each transaction request includes an associated priority value. A highest priority value of all pending transaction requests within the request queue is determined. An elevated priority value is selected when the highest priority value is higher than the priority value of an oldest transaction request in the request queue; otherwise the priority value of the oldest transaction request is selected. The oldest transaction request in the request queue with the selected priority value is then provided to the memory system. An arbitration contest with other requesters for access to the memory system is performed using the selected priority value.

A queuing requester for access to a memory system is provided. Transaction requests are received from two or more requestors for access to the memory system. Each transaction request includes an associated priority value. A request queue of the received transaction requests is formed in the queuing requester. Each transaction request includes an associated priority value. A highest priority value of all pending transaction requests within the request queue is determined. An elevated priority value is selected when the highest priority value is higher than the priority value of an oldest transaction request in the request queue; otherwise the priority value of the oldest transaction request is selected. The oldest transaction request in the request queue with the selected priority value is then provided to the memory system. An arbitration contest with other requesters for access to the memory system is performed using the selected priority value.

Circuits and systems for generating counter signals are provided herein. A circuit may comprise a shift register having a series of flip-flops. Each of the flip-flops of the series may be coupled to a clock. The shift register may generate a borrowing clock signal using an output of a flip-flop of the shift register, and a transition of the borrowing clock signal may be advanced by a number of clock cycles based on a position of the flip-flop of the shift register. The circuit may further comprise a clock divider circuit having a number of divide-by-N counters and a number of flip-flops. A divide-by-N counter may be coupled to a flip-flop of the shift register, and a flip-flop of the clock divider circuit may be coupled to one of the divide-by-N counters and to the clock.

Circuits and systems for generating counter signals are provided herein. A circuit may comprise a shift register having a series of flip-flops. Each of the flip-flops of the series may be coupled to a clock. The shift register may generate a borrowing clock signal using an output of a flip-flop of the shift register, and a transition of the borrowing clock signal may be advanced by a number of clock cycles based on a position of the flip-flop of the shift register. The circuit may further comprise a clock divider circuit having a number of divide-by-N counters and a number of flip-flops. A divide-by-N counter may be coupled to a flip-flop of the shift register, and a flip-flop of the clock divider circuit may be coupled to one of the divide-by-N counters and to the clock.

The present invention relates to data communication and electrical circuits. More specifically, embodiments of the present invention provide a clock and data recovery (CDR) architecture implementation for high data rate wireline communication links. In an embodiment, a CDR device includes a phase detector, a loop filter, and a fractional-N PLL. The fractional-N PLL generates output clock signal based on output of the loop filter. There are other embodiments as well.

A computing apparatus triggered by an edge of a supply-line signal with a pulse width counter includes: a clock circuit to supply clock signals to a pulse width counter from an output port of said clock circuit; said pulse width counter triggered by said clock signals to count the pulse width of a supply-line signal from a power supply line, to set a circuit status of said computing apparatus in accordance with said pulse width, and to output said circuit status to an edge-triggered computing unit; and the edge-triggered computing unit to do computing triggered by an edge of a supply-line signal, and to output computing result as the output of said computing apparatus in accordance with said circuit status. The circuit status of the computing apparatus is set in accordance with pulse width counter of supply-line signals .