Intel Corporation

Other

Jeffrey E Smith

Keng L Wong

Keith M Self

Gregory F Taylor

Yongping Fan

Roshan J Fernando

Kelly J Fitzpatrick

Hong H Chan

Ian A Young

Stephen S Pawlowski

Martin Spence Denham

John F Zumkehr

Jose A Maiz

James E Chandler

Clair C Webb

Prantik K Nag

William M Holt

Varin Udompanyanan

Timothy W Kelly

Glen R Wagner

Golnaz Kaveh

Downspout extension

Embodiments of the invention are generally directed to systems, methods, and apparatuses for reduced signal level support for memory devices. In some embodiments, a host includes one or more additional electrical contacts to provide a controllable voltage reference to a memory device. The host may also include driver circuitry to provide a driver signal to the memory device. In some embodiments, the driver signal is substantially symmetrical around the controllable voltage reference.

Reduced signal level support for memory devices

A pre-driverhas a data signal inputto receive a data signal, a pair of voltage inputsto receive supply voltages, and a data outputto provide an output voltage. A voltage clampis connected between a predetermined one of the voltage inputsand the data outputto clamp the output voltage with respect to the predetermined supply voltage. Other embodiments and methods are also described and claimed.

Voltage clamp

An on-die termination resistor includes three transistors and a resistor. The resistor keeps at least one of the transistors from entering the saturation region and therefore improves the I-V characteristics of the termination resistor.

On-die termination resistor with analog compensation

An output buffer generates an output signal having a plurality of low-to-high (LH) and high-to-low (HL) signal transitions, with each of the signal transitions having a clock-to-output delay. A pre-driver having a first and a second stage generates a reshaped waveform to trigger the LH and HL signal transitions of the output signal, with the first stage generating an initial waveform and the second stage modifying the initial waveform to generate the reshaped waveform based at least in part on a feedback reflective of a difference in the clock-to-output delays of the LH and HL signal transitions.

Output buffer with adjustment of signal transitions

A method and apparatus is presented where for transmitting data between two or more components. Data signals are sent in parallel with a clocking signal (e.g., on a bus) so that the data signal can be latched in relation to the clocking signal. For example, two clocking signals, out of phase from each other by 180 degrees, can be sent on bidirectional clocking signal lines and data signals can be sent on a data signal line, the component receiving the clocking and data signals can latch the data signals on each high-to-low transition of either of the two clocking signals. Using the method and apparatus of the present invention, skew problems seen with other bus systems can be reduced which leads to an increase in data transfer rates.

Method and apparatus for source synchronous data transfer

An analog process/voltage/temperature (PVT) compensated buffer includes a differential amplifier providing a first output signal indicative of a difference between an input signal and a reference signal. The input signal is compatible with a first type of logic. An active gain stage is coupled to translate the first output signal to a second output signal. The second output signal is compatible with a second type of logic. The differential amplifier and the active gain stage are coupled to receive a process/voltage/temperature (PVT) compensation signal. In one embodiment, the first type of logic is Gunning Transceiver Logic (GTL) and the second type of logic is complementary metal oxide semiconductor (CMOS) logic.

High speed analog compensated input buffer

Methods and apparatus for easing design constraints with respect to placement of computer system components and subsystems requiring relative synchronicity is described. In one embodiment the apparatus includes a first and a second integrated circuit wherein each integrated circuit includes a first phase-locked loop (PLL) formed on an integrated circuit die. A reference clock signal pin is coupled to the first PLL by a path of electrical length L1 for propagating a reference clock signal to the first PLL. A first PLL driver is coupled to the first PLL. A first PLL feedback pin is coupled to the first PLL by a path of electrical length L2, wherein L1.apprxeq.L2. The first and second integrated circuits are cascade-coupled by coupling the first PLL driver of the first integrated circuit to the reference clock signal pin of the second integrated circuit using a propagation path of electrical length L3. In one embodiment a feedback path of electrical length L4 couples the first PLL driver and feedback pin of the first integrated circuit such that L3.apprxeq.L4. In one embodiment L1, L2, L3, and L4 have corresponding physical lengths D1, D2, D3, and D4, wherein D1.apprxeq.D2 and D3.apprxeq.D4. The cascaded integrated circuits enable providing synchronicity between components of a same tier as well as between multiple tiers of a hierarchical computer system architecture.

Cascaded multiple internal phase-locked loops for synchronization of

Methods and apparatus for easing design constraints with respect to placement of computer system components and subsystems requiring relative synchronicity at different frequencies is described. In one embodiment the apparatus includes a first phase-locked loop (PLL) formed on an integrated circuit die. A reference clock signal pin is coupled to the first PLL by a path of electrical length L1 for propagating a reference clock signal to the first PLL. A first PLL feedback pin is coupled to the first PLL by a path of electrical length L2, wherein L1.apprxeq.L2. The apparatus includes a programmable counter coupled to the reference clock signal pin, the programmable counter providing a divided reference clock signal to the first PLL. In one embodiment, the method includes the step of providing a reference clock signal to a plurality of PLLs residing within a same integrated circuit. The outputs of at least some of the PLLs are coupled to corresponding output pins of the integrated circuit. The following steps are performed for each selected output pin coupled to provide a synchronized clock signal at the end of a propagation trace: a) determining an electrical length of the propagation trace; and b) providing a feedback trace from the output pin to a feedback pin of the corresponding PLL, wherein the feedback trace is a same electrical length as the propagation trace. A divided-by-n reference clock signal is then provided to at least one of the PLLs, wherein n is not equal to 1.

Multiple internal phase-locked loops for synchronization of chipset

An analog compensation circuit for providing process/voltage/temperature (PVT) bias compensation signals for input/output (I/O) circuitry within an integrated circuit includes a first current source coupled to a first node. A first load coupled to the first current source and a second node provides a first reference voltage. A voltage divider coupled between the first and second nodes provides a current source bias voltage to the first current source. A differential amplifier generates a first bias compensation signal as feedback for the first current source in accordance with the difference between the first reference voltage and a second reference voltage. With the addition of logic level bias converters, the compensation circuitry is capable of providing bias compensation signals to multiple logic families. The bias compensation signals can be applied to current sources used to control the functioning of integrated circuit I/O circuitry so that the I/O circuitry operates substantially independently of PVT variations.

Analog compensation circuitry for integrated circuit input/output

An apparatus and a method for easing design constraints with respect to placement of computer system components and subsystems requiring relative synchronicity are described. In one embodiment, the apparatus includes a first phase-locked loop (PLL) coupled to a reference clock pin by a path of length L1 and a first PLL feedback pin by a path of length L2 such that L1.apprxeq.L2. In another embodiment, the apparatus includes a second PLL coupled to the reference clock pin by a path of length L3. The second PLL is coupled to an internal core of the integrated circuit by a path of length L4 such that L3.apprxeq.L4. In one embodiment, a computer system incorporating the apparatus includes a first propagation path of length L5 coupled to the first PLL output pin. The first PLL output pin is coupled to the first PLL feedback pin by a path of length L6 such that L5.apprxeq.L6. The choice of electrical lengths allows relative synchronicity between the clock signals propagated to the internal core and the end of the first propagation path.

A method and apparatus for reducing contention in an integrated circuit during power-up. According to one aspect of the invention, an initialization circuit is included in an integrated circuit. In response to receiving Vcc, the initialization circuit generates a substitute clock signal and a substitute reset signal. The substitute clock signal and substitute reset signal are substituted for an off chip generated clock signal and an off chip generated reset signal during power-up until a predetermined condition is met. In response to receiving the substitute clock signal and the substitute reset signal, a plurality of circuits on said integrated circuit are initialized.

Power-on initializing circuit

A method and an apparatus for generating an output voltage for an integrated circuit having multiple power supplies. A comparator circuit is coupled to receive power supply lines from the power bus of an integrated circuit. The power supply lines received from the power bus have different voltages which may vary depending on the particular application. The comparator compares the voltage potentials present on the power supply lines and determines which power supply line carries a voltage having the highest potential. The comparator then generates a corresponding select signal wherein the value of the select signal indicates which particular power supply line has the highest voltage potential. A multiplexor is coupled to receive the select signal as well as the power supply lines from the power bus. Based on the value of the select signal, the multiplexor generates the output voltage in response to the select signal wherein the output voltage is substantially equal to the voltage potential of the power supply line having the highest voltage potential.

Differential power bus comparator

A clock distribution system and clock interrupt system for an integrated circuit device. Ignoring effects associated with the matched stages, the present invention includes a clock distribution and interrupt system for providing clock signals with less than 100 picoseconds of skew to various components of an integrated circuit device. The present invention utilizes several stages of drivers to evenly supply the distributed clock signals and each stage has RC matched input lines. The present invention advantageously locates the matched stages and clock drivers within the power supply ring of the integrated circuit located on the periphery of the microprocessor topology. This is done in order to better predict the topology surrounding these lines to match the capacitance of these lines. Further, this metal level offers a larger width dimension line (since as a top layer it may be thicker) having less resistance per unit area and also generally avoids spatial competition with other IC components and circuitry. The present invention additionally offers the capability of selectively powering down various components within the integrated device with a power management unit and enable network that is included as a component of the clock distribution system.

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Aloha, OR, United States of America

Jeffrey E Smith