Altera Corporation

John D Lam

Rakesh H Patel

Chong H Lee

Vinson Chan

Wilson Wong

John E Turner

Ramanand Venkata

Henry Y Lui

Malik Kabani

Arch Zaliznyak

Tony K Ngai

Sammy S Cheung

A skew-tolerant, glitch-free reset distribution apparatus and method are provided in an intellectual property (IP) block that supports a multi-channel input/output protocol. During reset mode, synchronizers are used to create more predictable timing, to pipeline the propagation delay, and to tolerate RC-induced skews of up to a clock period in routing a reset signal to all the channels and within the channels in an IP block. Two control signals, which are available from programmable logic resource core circuitry, are used to control the input of the reset signal into the IP block. Because the control signals are designed to be glitch-free, the reset signal is therefore also glitch-free, thus preventing the IP block from inadvertently transitioning into or out of reset mode.

Apparatus and method for reset distribution

A serial data interface for a programmable logic device includes a receiver that deserializes a plurality of channels of received serial data using a recovered clock signal or a phase-aligned received clock signal. Byte boundaries are initially assigned, perhaps arbitrarily, and the deserialized signal is sent to the programmable logic core of the programmable logic device. Programmable logic in the core monitors the byte boundaries on each channel based on the criteria, including any user-defined parameters, programmed into the logic. If a boundary misalignment is detected, a signal is send from the core to bit-slipping circuitry on that channel of the interface to adjust the boundary. The signal could instruct the bit-slipping circuitry to adjust the boundary by the number of bits needed to correct the alignment. Alternatively, the bit-slipping circuitry could operate iteratively, adjusting the boundary by one bit, each cycle, until the signal stops indicating misalignment.

Byte alignment for serial data receiver

A technique and circuitry interfaces a programmable logic integrated circuit compatible with one voltage level to other integrated circuits compatible with a different voltage level. In particular, an on-chip voltage less than the external supply level of the programmable logic integrated circuit is provided to a core portion of a programmable logic integrated circuit by way of a conversion transistor. In an embodiment, the layout (or physical structure) of the conversion transistor is distributed surrounding the core portion. Externally, the programmable logic integrated circuit will interface with an external supply voltage level. The input and output signals to and from the programmable logic integrated circuit will be compatible with the external supply level.

Programmable logic with lower internal voltage circuitry

A technique provides an on-chip voltage to a core portion of an integrated circuit by way of a conversion transistor. The on-chip voltage may be a reduced internal voltage, less than the VCC of the integrated circuit. In an embodiment, the layout (or physical structure) of the conversion transistor is distributed surrounding the core portion. By providing the core with a reduced voltage, the integrated circuit may interface with other integrated circuits compatible with different voltage levels.

Circuitry for a low internal voltage

Circuitry for a low internal voltage integrated circuit

An output buffer has internal circuitry connected between an input node and an output node. The internal circuitry includes a quiet voltage supply connected to a first set of transistors of the internal circuitry and a noisy voltage supply connected to a second set of transistors of the internal circuitry. The noisy voltage supply is at a voltage level higher than the quiet voltage supply. The first set of transistors and the second set of transistors provide isolation between the noisy voltage supply and the quiet voltage supply. The first set of transistors and the second set of transistors also provide complete digital high and low internal signal levels by using at least one transistor operative to supplement the complete shut-off and turn-on of transistors of the first set of transistors and the second set of transistors. The output buffer also features a ground bounce circuit, a slew rate control circuit, a transition accelerator circuit, a Personal Computer Interface (PCI) compatibility circuit, and a PCI control circuit.

High performance output buffer

A technique and circuitry for interfacing an integrated circuit manufactured using technology compatible with one voltage level to other integrated circuits compatible with a different voltage level. In particular, the integrated circuit is fabricated using technology compatible with an internal supply voltage level. Externally, the integrated circuit will interface with an external supply voltage level, above the internal supply voltage. The input and output signals to and from the integrated circuit will be compatible with the external supply level. The integrated circuit may include a voltage down converter (1330) and level shifter (1317).

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Fremont, CA, United States of America

John D Lam