Abstract: An on-chip I/O timings measurement circuit that improves measurement accuracy compared to conventional external test methods. This circuit guarantees AC timing specifications that are too small for the measurement capabilities of today's high-frequency memory testers. This system in incorporated into the SRAM via the JTAG interface and a JTAG private instruction. A private instruction refers to an unused instruction from the industry-standard public instruction set. Private instructions are usually reserved for the manufacturer, but may be provided to the user as an enhancement to the standard JTAG instruction set.

Abstract: An off-chip driver (OCD) circuit including a clamp circuit to limit overdrive is provided. The circuit comprises an input signal which is inverted to provide an output signal. The driver circuit is comprised of a source-follower transistor to pull-down the output signal. The clamp circuit actively feeds back the source-follower potential to slow down the OCD and minimize ground bounce and noise that causes circuits to fail and signal integrity to be corrupted. The simple drive and clamp circuit is comprised of three transistors, one resistor, and one capacitor. The OCD slew rate is controlled by a current source and provides an output that changes between a positive voltage and ground. The circuit limits dv/dt without using a large resistor as a source follower, hence minimizing the adverse effect on performance.

Abstract: A pulse generator comprising a delay circuit uses a series of "n" delay stages to generate pulses that do not have distorted duty cycles. The output of the delay stage "n" feeds back to reset the delay stage "n-2". The output of each of the delay stages initially changes from a first logic state to a second logic stage at the leading edge of a pulse. The output of each delay stage switches back to the first logic state, or the trailing edge of the pulse, upon receipt of the feedback signal from a subsequent delay stage. The wave characteristics depend only on the rising edge of the pulse because the rising edge of the pulse of a future stage generates the falling edge of the current stage.

Abstract: A delay circuit which employs a Miller effect to delay a signal while driving a subsequent amplifier stage. The Miller effect is dependent upon loading of the circuits on an integrated circuit upon which the delay circuit is implemented, which allows the delay circuit to compensate its delay in relation to other process variation delays present on the integrated circuit. The delay circuit has a first delay stage which delays an input signal and drives a second stage. The delay circuit incorporates a dummy drive stage which adds loading to the first delay stage. In addition, the dummy stage experiences dynamic loading of the delay chain between the first and second stages which allows the coupling of the effect of this dynamic loading back to the first stage through the Miller effect.

Abstract: A noise detection and delay receiver circuit includes a circuit input and output and a plurality of individual receiver circuits connected to the input having trip points which range from a low trip point to a high trip point. Edge detect circuitry and delay circuitry are used to prevent the output from changing back to the previous state for a period of time immediately after it has just changed state. Multiple transitions of the input voltage across the trip points of the individual receivers are used to delay the response until noise has settled out of the input signal.

Abstract: A latch circuit employs state-walk logic that makes the transition from "set" to "latched" states without the need for multiple phases, critical timing or introduction of extra periods into any timings to account for worst case scenarios. The has particular application to row address receivers for dynamic random access memories (DRAMs) and, in its basic form, comprises a pair of identical receiver circuits of opposite logic state when off, with clock and data inputs and true and complementary outputs. The receivers are turned on by an activating clock signal. When the receivers are enabled, address data is evaluated as soon as it is received causing the latch to be set. This is the first step in the "state walk" of the latch. The outputs of the latch are fed back to turn off the receiver circuits completing the second step of the "state walk". The circuit now ignores any changes in the input address data, thus latching the input data.

Abstract: A circuit for detecting an input signal, the circuit having an input node and an output node, includes a first latch having a set input coupled to the input node, for detecting falling transitions at the input node. A second latch having a set input coupled to the input node, detects rising transitions at the input node. A first logic device, responsive to outputs of the first and second latches, detects that an input signal has been received at both the first and second latches. A second logic device, responsive to a complement output of both the first and second latches, resets both the first and second latches.

Abstract: The sense amplifier registers (SARs) servicing the arrays of a dynamic random access memory (DRAM) located on a semiconductor chip with a processor are all maintained at full power while unaccessed arrays are powered down to conserve power. Accessing circuits for the DRAM permit accessing by the processor of word length segments of each of the SARs independently of one another so that the SARs function as a read/write cache for the processor.

Abstract: A bandgap reference generator providing a reference voltage V.sub.R from a power supply voltage V.sub.DD. The bandgap reference generator includes a bandgap reference circuit and a voltage regulation circuit coupled thereto. The voltage regulation circuit operates to supply power to the bandgap reference circuit such that the voltages at a first internal control node and a second internal control node are equal, wherein the first internal control node and the second internal control node are disposed on different current paths within the bandgap reference circuit. By equalizing voltages at these internal control nodes, device stress within the bandgap reference circuit is reduced. Kick-start circuits for the voltage regulation circuit and the bandgap reference circuit are also included within the bandgap reference generator. In addition, output stage processing can be incorporated to transform an outputted reference voltage V.sub.R from a low stress operating point to a desired reference voltage V.sub.REF.

Abstract: The sense amplifier registers (SARs) servicing the arrays of a dynamic random access memory (DRAM) located on a semiconductor chip with a processor are all maintained at full power while unaccessed arrays are powered down to conserve power. Accessing circuits for the DRAM permit accessing by the processor of word length segments of each of the SARs independently of one another so that the SARs function as a read/write cache for the processor.

Abstract: The sense amplifier registers (SARs) servicing the arrays of a dynamic random access memory (DRAM) located on a semiconductor chip with a processor are all maintained at full power while unaccessed arrays are powered down to conserve power. Accessing circuits for the DRAM permit accessing by the processor of word length segments of each of the SARs independently of one another so that the SARs function as a read/write cache for the processor.

Abstract: A fuse download system for programming decoders for redundancy. Auxiliary fuse banks have sets of fuses that store logic states that (a) select a redundant decoder and (b) indicate the address of a faulty row/column of memory cells. When the chip is first powered up, each set of fuses is accessed and downloaded to program selected redundant decoders. Because the fuse sets can be dynamically assigned to redundant decoders on an any-for-any basis, the fault tolerance of the redundancy system is enhanced.

Abstract: Multichip integrated circuit packages and systems of multichip packages having reduced interconnecting lead lengths are disclosed. The multichip package includes a multiplicity of semiconductor chip layers laminated together in a unitized module. A first metallization pattern is connected to the integrated circuit chips on at least one side surface of the unitized module. In addition, at least one end surface of the module contains a second metallization pattern which is configured to facilitate connection of the package to an external signal source, such as another multichip package. The system includes at least two such packages which are electrically coupled via either metallization patterns provided on the end surface of the packagers. If required, a plurality of multichip packages can be directly coupled into the system in an analogous manner. Further specific details of the multichip package and the system of multichip packages are set forth herein.

Abstract: A memory system and a unique memory chip is disclosed wherein multiple islands on a chip can be separately accessed by separate island controllers whereby concurrent use of the several islands or arrays on a chip can be achieved.