Xilinx, Inc.

Sk Hynix Memory Solutions Inc.

Xlinx, Inc.

Gubo Huang

Shi-dong Zhou

Andy T Nguyen

Xiaobao Wang

Andrew Tabalujan

Kwok Wah Yeung

Meng-Kun Lee

Ronald L Cline

Hy V Nguyen

Shankar Lakkapragada

Sing-Keng Tan

Shidong Zhou

Fu-Hing Ho

Fariba Farahanchi

Shi Dong Zhou

Examples herein describe techniques for testing a receiver interface on a die. In one embodiment, the die includes tester circuitry which includes a digital to analog convertor (DAC) which outputs an analog test signal to a selector circuit (e.g., a multiplexer) which forwards the analog test signal to a receiver. By varying the analog test signal, the tester circuitry can identify one or more trip points corresponding to the receiver. That is, by monitoring the output of the receiver, a testing application can determine when the output of the receiver switches states thereby indicating that the analog test signal at the input of the receiver corresponds to the trip point of the receiver. In this manner, internal circuitry (e.g., the tester circuitry) can be used to test a receiver interface that may otherwise be inaccessible.

Testing an integrated circuit receiver in a package using a varying analog voltage

Examples of the present disclosure provide example devices that include an integrated circuit that has debugging capability. In some examples, a device includes an integrated circuit die. The integrated circuit die includes an input/output (IO) base cell and a debug port. The IO base cell has an interface node and a feedback node. The interface node is configured to be coupled to memory, such as via an interposer, for communication therebetween. The IO base cell is configurable to selectively output to the feedback node a signal that is on the interface node. The debug port has an input node and an output node. The input node is electrically connected to the feedback node. The debug port is configurable to selectively output to the output node a signal that is on the input node. The output node is configured to be coupled to a pin exterior to the integrated circuit die.

Electronic device including integrated circuit with debug capabilities

Examples herein describe a die that includes a testing system (e.g., testing circuitry) for measuring the actual resistance of on-die resistors. When testing the die, an I/O element (e.g., a solder bump) can be used to sweep a voltage across the on-die resistor. The testing system identifies when the voltage across the on-die resistor reaches a predefined reference voltage and measures the corresponding current. Using the measured current and the reference voltage, the testing system can identify the actual resistance of the on-die resistor. In one embodiment, the on-die resistor is tunable such if the on-die resistor has a divergent value, the die can adjust its resistance value to the desired value.

On-die resistor measurement

A second controller is communicated with from a first controller via an interface. Storage is also communicated with from the first controller via the interface. The first controller is configured to be a master on the interface and the second controller and the storage are configured to be targets on the interface.

Interface between multiple controllers

In an example implementation, a level-shifter circuit in an integrated circuit (IC) includes a plurality field-effect transistors (FETs) coupled to provide: a first inverter having an input port configured to receive an input signal having a first supply voltage, an output port, and a bias port; a second inverter having an input port coupled to the output port of the first inverter, an output port, and a bias port coupled to a second supply voltage; a diode-connected FET coupled between the second supply voltage and the bias port of the first inverter; a first FET in parallel with the diode-connected FET having a gate coupled to the output of the second inverter; and a second FET in parallel with the diode-connected FET and the first FET having a gate configured to receive a mode select signal.

Programmable single-supply level-shifter circuit

An integrated circuit has an E-fuse sense circuit configured to produce a READ voltage according to a fuse resistance of an E-fuse during a READ operation. The integrated circuit also has a reference sense circuit configured to produce a reference voltage according to a reference resistance of an on-chip reference resistor during the READ operation. The reference sense circuit replicates the E-fuse sense circuit. The E-fuse sense circuit and the reference sense circuit are coupled to a comparator that produces a bit value according to a difference between the READ voltage and the reference voltage.

E-fuse read circuit with dual comparators

A programmable differential signaling system includes a programmable bias generator and a plurality of input/output modules. The programmable bias generator is operably coupled to generate a first global bias signal and a second global signal based on desired signal properties of one of a plurality of differential signaling conventions. The a plurality of input/output modules is operably coupled to convert between differential signaling and single ended signaling, wherein actual signal properties of the differential signaling are regulated based on the first and second global bias signals to substantially equal the desired signal properties.

Programmable differential signaling system

Low current differential signal/swing I/O interfaces and techniques can be implemented. An output interface converts input data signals to differential current signals for transmission over transmission lines. When the differential current signals are received by an input interface, they are converted to differential voltage signals and appropriately amplified.

Apparatus and method for low current differential swing I/O interface

Apparatus and method for providing reference voltages for differential signaling with tracking of output differential voltage relative to output offset voltage are described. A swing reference voltage, an offset reference voltage, a swing feedback voltage, and an offset feedback voltage are obtained. Differences between pairs of these voltages are differentially amplified to produce first and second bias voltages. Pull-up and pull-down voltages are driven partially responsive to the first bias voltage and the second bias voltage to provide first and second control voltages. The first control voltage may be provided to a first resistance for the driving of the first pull-up and pull-down voltages. The second control voltage may be provided to a second resistance for the driving of the second pull-up and pull-down voltages. The first control voltage and the second control voltage may be provided to a third resistance.

Low voltage differential signaling with output differential voltage to output offset voltage tracking

A test-mode circuit allows the same pad of a semiconductor device to be used as a test pad during test operations and as an I/O pad during normal operations. The test-mode circuit is coupled between the pad and a reference signal (Vbg) of the device, and in response to a control signal (CTRL) either couples the pad and the reference signal (Vbg) together or isolates the pad and the reference signal (Vbg) from each other. The test-mode circuit includes at least one NMOS transistor (MN) and a PMOS transistor (MP) connected in series between the pad and the reference signal (Vbg). During normal operation, the NMOS transistor (MN) isolates the reference signal (Vbg) from the pad, and the PMOS transistor (MP) compensates for voltage undershoot conditions at the pad.

Ground bounce protection circuit for a test mode pin

A power-on reset circuit for generating a reset signal for an associated IC device includes a pull-up resistor connected between a supply voltage and a tracking node, a pull-down transistor connected between the tracking node and ground potential, and a voltage divider circuit connected between the supply voltage and ground potential. The voltage divider circuit has a first ratioed voltage node coupled to the gate of the pull-down transistor. For some embodiments, the voltage divider circuit includes a first resistor connected between the voltage supply and the first ratioed voltage node, a second resistor connected between the first ratioed voltage node and a second ratioed voltage node, a third resistor connected between the second ratioed voltage node and ground potential, and a shunt transistor connected between the second ratioed voltage node and ground potential has a gate responsive to the reset signal.

CMOS power on reset circuit

An input circuit includes a first buffer having a first power terminal coupled to a first supply voltage, a second power terminal coupled to ground potential, an input to receive an input signal, and an output to generate a first output signal, a second buffer having a first terminal coupled to a second supply voltage, a second terminal coupled to a bias node, an input to receive the input signal, and an output to generate a second output signal, and a control circuit configured to selectively connect the bias node either to the second supply voltage or to ground potential in response to an enable signal.

Low voltage input circuit with high voltage tolerance capability

A technique and circuit implementation are described for automatically detecting a change in a power supply voltage and selectively reconfiguring a circuit for optimized performance at the changed voltage. One application of particular interest is an auto-detect level shifter. The auto-detect level shifter can be used in an output driver and can be automatically enabled if it is needed to optimize performance for various I/O standards, including those that operate at different voltages.

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Milpitas, CA, United States of America

Gubo Huang