Silicon Laboratories Inc.

Subrata Roy

Xiaodong Wang

Axel Thomsen

Jinwen Xiao

Clayton H Daigle

Xiaohui Wang

Arjun Singhal

A method updates a low frequency count value at a first frequency in an active mode and maintains the low frequency count value in the low power mode. Updating the low frequency count value includes updating a fractional counter in response to a first clock signal, updating an integral counter in response to a second clock signal, and generating the second clock signal based on the fractional count and the first clock signal. The first clock signal has a second frequency. The first frequency is lower than the second frequency. Updating the low frequency count value may include adjusting the low frequency count value in response to exiting the low power mode based on a difference between a current value of a real time clock counter and a prior value of the real time clock counter stored upon entry into the low power mode.

Low power low frequency counter for software use

A data producer stores input data in a buffer in response to a slow clock signal and provides read data from the buffer in response to a read pointer signal. A data movement circuit reads the input data from the buffer using the read pointer signal and provides an update read pointer signal in response to reading the input data. The data movement circuit operates in response to a fast clock signal, and includes a metastable-free synchronizer circuit having inputs for receiving the update read pointer signal, the slow clock signal, and the read pointer signal, and an output for providing a synchronized read pointer signal equal to the read pointer signal except between a change in the read pointer signal while the slow clock signal is active until an inactivation of the slow clock signal. The buffer provides the read data in response to the synchronized read pointer signal.

Data transmission between clock domains for circuits such as microcontrollers

A technique includes clocking a processor; and in response to the processor providing a signal indicating that the processor is transitioning between a first power state that is associated with a first power consumption and a second power state that is associated with a second power consumption different than the first power consumption, changing a frequency of the clocking.

Clocking a processor

A method includes assigning a plurality of pads of an integrated circuit (IC) to a direct memory access (DMA) channel of the IC; and storing DMA requests associated with the pads in a queue such that at a given time, the queue stores data indicative of DMA requests that are associated with more than one pad.

Pad direct memory access interface

An integrated circuit (IC) includes a plurality of pads adapted to communicate signals with a circuit external to the IC, and a first mixed signal interface block coupled to a first pad in the plurality of pads, where the first mixed signal interface block is adapted to receive a first trigger signal from the circuit external to the IC and to provide a second trigger signal. The IC further includes a second mixed signal interface block coupled to a second pad in the plurality of pads, where the second mixed signal interface block is adapted to receive and track a first input signal from the circuit external to the IC in a first mode of operation of the IC. The second mixed signal interface block is further adapted to generate, in response to the second trigger signal, a first output signal based on the first input signal and to provide the first output signal to a digital core of the IC in a second mode of operation of the IC, where the power consumption of the IC is lower in the first mode of operation than in the second mode of operation.

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Austin, TX, United States of America

Subrata Roy