Abstract: Automated clock relationship detection may quickly and reliably detect a clock relationship with minimal latency while reducing problems due to metastability occurring at a solitary instant or extended over multiple clock periods. Automated clock relationship detection between two clocks may comprise (a) a shift register synchronizer that reduces the possibility of metastability while capturing and temporarily storing samples of the first clock in response to cycles of the second clock and (b) an evaluator that processes the samples to determine the relationship. A clock relationship detector may also determine the relationship of two clocks by arbitrating a plurality of preliminary determinations of the relationship. Delays may be applied so that each of several detectors receives a clock at a different time, which may avoid metastability in the majority of detectors. The relationship may be used to reliably determine an operating mode of logic driven by one of the clocks.

Abstract: Automated clock relationship detection may quickly and reliably detect a clock relationship with minimal latency while reducing problems due to metastability occurring at a solitary instant or extended over multiple clock periods. Automated clock relationship detection between two clocks may comprise (a) a shift register synchronizer that reduces the possibility of metastability while capturing and temporarily storing samples of the first clock in response to cycles of the second clock and (b) an evaluator that processes the samples to determine the relationship. A clock relationship detector may also determine the relationship of two clocks by arbitrating a plurality of preliminary determinations of the relationship. Delays may be applied so that each of several detectors receives a clock at a different time, which may avoid metastability in the majority of detectors. The relationship may be used to reliably determine an operating mode of logic driven by one of the clocks.

Abstract: A method of defective pixel address detection for image sensor. During the image sensor is tested, a number of defective pixel addresses of the image sensor are stored into a memory element and indexed. Each of the pixels of the image sensor is read in sequence and then compared with the indexed defective pixel address. If the sensor address is equal to the indexed defective pixel address, a defective pixel flag is outputted and then the index is increased by one. If the sensor address is not equal to the defective pixel address, the defective pixel address is compared with an empty signature. After the index is increased or the defective pixel address is not an empty signature, the detection process is continued.

Abstract: A method of bad pixel correction for an image sensor. The image sensor has a plurality of rows, and each row includes at least one dark pixel on both ends of the row and valid pixels. The method comprises the steps of inserting a dummy value with a bad pixel flag into a first in first out (FIFO), wherein the dummy value is used for replacing a value of the dark pixel; determining whether a control signal is asserted, wherein the control signal is used for indicating that a current pixel is the valid pixels when the control signal is asserted; writing the values of the valid pixels into the FIFO when the control signal is asserted; determining whether the control signal is deasserted; and inserting a dummy value with a bad pixel flag into the FIFO when the control signal is deasserted.

Abstract: An apparatus for dark level integration comprises a programmable gain amplifier for amplifying signal levels from the pixel. A calibration signal generator for receiving a first calibration signal and a bad pixel signal to generation a second calibration signal, wherein the second calibration signal indicates the existence of the bad pixel. A dark current calibration integrator couples to the programmable gain amplifier and the calibration signal generator for receiving the amplified signal levels from the programmable gain amplifier and the second calibration signal to generate a control signal to the programmable gain amplifier.

Abstract: A method of defective pixel address detection for an image sensor. The method comprises comparing a defective pixel address with a sensor address; outputting a defective pixel flag if the sensor address is equal to the defective pixel address; increasing an index by one; increasing the index by one if the sensor address is larger than the defective pixel address and the index value is not equal to zero, otherwise performing a following step; increasing the index by one if the sensor address is larger than the defective pixel address and the index value is equal to zero and a frame begins, otherwise performing a following step; comparing the defective pixel address with an empty signature; increasing the index by one if the defective pixel address is equal to the empty signature; and returning to the beginning step if the defective pixel address is not equal to the empty signature.