Data line with dynamic pull-up circuit

A data transfer circuit in a programmable logic device having a set of configurable logic blocks, comprising:

• a data conductor;
• a circuit element providing a current path pulling the data conductor to a target voltage;
• a plurality of data-in drivers, having inputs connected to configurable logic blocks in the set and outputs connected to the data conductor, which act in one state to pull the data conductor from the target voltage to a lower voltage, and act in another state to present high impedance to the data conductor;
• and
• a dynamic element which connects an additional current path to pull the data conductor to the target voltage during voltage transitions on the data conductor from the lower voltage to the target voltage, and which disconnects the additional current path when the transition is complete.

A pull-up circuit for a data line, comprising:

• a resistive element connected between the data line and a source of a supply voltage;
• a first transistor having a gate, a drain and a source, the source connected to the source of the supply voltage;
• a second transistor having a gate, a drain and a source, the drain connected to the drain of the first transistor, and the source connected by a current path to the data line;
• an inverter, having an input connected to the data line and an output connected to the gate of the first transistor;
• and
• a Schmitt trigger, having an input connected to the data line and an output connected to the gate of the second transistor.

A data transfer circuit, comprising:

• a data conductor;
• a circuit element providing a current path pulling the data conductor to a target voltage;
• a plurality of data-in drivers connected to the data conductor which act in one state to pull the data conductor from the target voltage to a driven voltage, and act in another state to present high impedance to the data conductor;
• and
• a dynamic element which connects an additional current path to pull the data conductor to the target voltage only during voltage transitions on the data conductor from the driven voltage to the target voltage, and which disconnects the additional current path otherwise.

A data transfer circuit in a programmable logic device having a set of configurable logic blocks, comprising:

• a data conductor;
• a circuit element providing a current path pulling the data conductor to a target voltage;
• a plurality of data-in drivers, having inputs connected to configurable logic blocks in the set and outputs connected to the data conductor, which act in one state to pull the data conductor from the target voltage to a lower voltage, and act in another state to present high impedance to the data conductor;
• and
• a dynamic element which connects an additional current path to pull the data conductor to the target voltage only during voltage transitions on the data conductor from the lower voltage to the target voltage, and which disconnects the additional current path otherwise.