Abstract:
Described embodiments provide for, in a SerDes device, an adaptation process that adjusts data path gain through programmable-bias based on process, voltage, temperature (PVT) and data rate changes. Such adaptation process extends bias current dynamic range, and low frequency gain can be programmed to a desired target range of values for a given variable gain amplifier (VGA) setting at any PVT and data rate corner. A receive (RX) data path structure auto-adapts data path gain through programmable bias based on sensed PVT and data rate changes. The low frequency attenuation/gain range is extended, and can be programmed to a desirable targeted range by a SerDes device RX adaptive process for a given VGA and linear equalizer (LEQ) setting at any given PVT and data rate condition.
Abstract:
Described embodiments provide for, in a SerDes device, an adaptation process that adjusts data path gain through programmable-bias based on process, voltage, temperature (PVT) and data rate changes. Such adaptation process extends bias current dynamic range, and low frequency gain can be programmed to a desired target range of values for a given variable gain amplifier (VGA) setting at any PVT and data rate corner. A receive (RX) data path structure auto-adapts data path gain through programmable bias based on sensed PVT and data rate changes. The low frequency attenuation/gain range is extended, and can be programmed to a desirable targeted range by a SerDes device RX adaptive process for a given VGA and linear equalizer (LEQ) setting at any given PVT and data rate condition.
Abstract:
In described embodiments, process, voltage, temperature (PVT) compensation in a serializer/deserializer (SerDes) device employs a closed loop adaptation compensation that is incorporated into the SerDes receiver adaptation process. A detection method, where the adapted decision feedback equalizer (DFE) target level (e.g., tap H0) is monitored, employs this DFE target level when implementing a closed loop variable gain amplifier adaptation. The DFE target level in conjunction with the VGA level is used to control the PVT setting to maintain target SerDes data path gain by detecting aPVT corner condition. The detected PVT corner condition is employed to generate a control signal to further adjust the LEQ and DFE data path differential pair gain as required by the PVT condition.
Abstract:
In described embodiments, process, voltage, temperature (PVT) compensation in a serializer/deserializer (SerDes) device employs a closed loop adaptation compensation that is incorporated into the SerDes receiver adaptation process. A detection method, where the adapted decision feedback equalizer (DFE) target level (e.g., tap H0) is monitored, employs this DFE target level when implementing a closed loop variable gain amplifier adaptation. The DFE target level in conjunction with the VGA level is used to control the PVT setting to maintain target SerDes data path gain by detecting aPVT corner condition. The detected PVT corner condition is employed to generate a control signal to further adjust the LEQ and DFE data path differential pair gain as required by the PVT condition.
Abstract:
Described embodiments provide for, in a clock and data recovery (CDR) circuit, detection of loss of acquisition and CDR restarting with corrective integral accumulator register seeding and gearshift restarting. In described embodiments, a mechanism is employed to cause faster loss of lock condition if the CDR circuit directed on an incorrect acquisition trajectory, actual loss of CDR lock is then detected, and CDR acquisition is recovered with corrective integral accumulator seeding.
Abstract:
A tap coefficient control circuit and a method for controlling a tap coefficient for a decision feedback equalizer are disclosed. The method includes adjusting a correction voltage applied to the tap coefficient based on a first tap quantization and detecting a decision feedback equalizer tap convergence. After the decision feedback equalizer tap convergence is detected, the method adjusts the correction voltage applied to the tap coefficient based on a second tap quantization, wherein the second tap quantization is different from the first tap quantization.