Vlsi Technology, Inc.

Microchip Technology Inc.

Microchip Technology Incorprated

Joseph Alan Thomsen

David R Evoy

Laura Elisabeth Simmons

Marty L Long

Gary D Hicok

Lonnie Calvin Goff

Gary A Walker

Timothy J Phoenix

Randy L Yach

David M Susak

Joseph W Triece

Franklyn H Story

Henry M Pena

Ned D Garinger

James C Steele

Brian E Boles

Russell E Cooper

Richard W Ulmer

Brian N Fall

Jeffery M Michelsen

W Henry Potts

Timothy J Powers

Thomas J Ebzery

James R Bartling

Guoli Wang

Hrushikesh Nalubola

Bruce E Cairns

Mitchel Obolsky

John Bree

Gordon E Luke

An internal integrated circuit clock oscillator is automatically synchronized to an external frequency reference by counting the number of periods of the internal clock oscillator (hereinafter 'count') that occur within a period of a lower frequency external frequency reference then comparing the count to the reference count. When the reference count is greater than the count, the frequency of the internal clock oscillator is increased. When the reference count is less than the count, the frequency of the internal clock oscillator is decreased. When the reference count and the count are substantially the same, the frequency of the internal clock oscillator is not changed.

Automatic synchronization of an internal oscillator to an external frequency reference

A digital processor is coupled to a processor programmer through a single programming connection (e.g., terminal, pin, etc.) coupled to the single conductor programming bus. The processor programmer comprises an instruction encoder/decoder, a Manchester encoder, a Manchester decoder, a bus receiver and a bus transmitter. The digital processor comprises an instruction encoder/decoder, a Manchester encoder, a Manchester decoder, a bus receiver, a bus transmitter, a central processing unit (CPU), and a program memory. The instruction encoder/decoder is coupled to the CPU and the program memory. The bus receivers and bus transmitters are coupled to the single conductor programming bus which is coupled to a connection, e.g., terminal, pin, ball, etc., on an integrated circuit package containing the digital processor. The instruction encoder/decoder is coupled to a programming console, e.g., a personal computer, workstation, etc.

Programming a digital processor with a single connection

A digital processor may be coupled to a processor programmer through a single conductor programming bus. The digital processor and the processor programmer, each may have a single programming connection (e.g., terminal, pin, etc.) coupled to the single conductor programming bus. The processor programmer may comprise an instruction encoder/decoder, a Manchester encoder, a Manchester decoder, a bus receiver and a bus transmitter. The bus receiver and bus transmitter may be coupled to the single connection that may be coupled to the single conductor programming bus. The instruction encoder/decoder may be coupled to a programming console, e.g., a personal computer, workstation, etc. The digital processor may comprise an instruction encoder/decoder, a Manchester encoder, a Manchester decoder, a bus receiver, a bus transmitter, a central processing unit (CPU), and a program memory. The bus receiver and bus transmitter may be coupled to the single connection, e.g., terminal, pin, ball, etc., on an integrated circuit package containing the digital processor. The single connection may be coupled to the single conductor programming bus. The instruction encoder/decoder may be coupled to the CPU and the program memory.

A five volt tolerant integrated circuit signal pad having an initial fast pull-up to three volts and then operating as an open drain output with an external resistor for pulling up the output from about three volts to about five volts. The initial fast (active) pull-up is accomplished with active devices that reduces the overall pull-up time of a newer technology (lower operating voltage) integrated circuit output when transitioning from a logic 0 to a logic 1. Circuits of the integrated circuit output driver protect the internal operating circuit nodes from excessive voltage and leakage currents that would otherwise result from a voltage on the signal pad that is more positive than the operating voltage of the integrated circuit.

Five volt tolerant integrated circuit signal pad with three volt assist

A filter register bank, for example, for a CAN module provides parallel and serial access. The filter bank comprises a plurality of memory cells arranged in a matrix of columns and rows, wherein for parallel access all memory cells within a row are selectable and coupled with a first plurality of bus lines and for serial access all memory cells within a column are selectable and coupled with a second plurality of bus lines.

Register bank

An electronic circuit includes a non-volatile memory on an integrated circuit that has several memory cells. The cells each have a voltage state and a gate. A gate bias circuit on the integrated circuit is coupled to the gates of the memory cells. The gate bias circuit includes at least a read voltage and a margin voltage. A detection circuit on the integrated circuit is coupled to the cells. The detection circuit includes a comparator and a reference voltage. The reference voltage and the voltage state of one of the cells are coupled to the comparator. The detection circuit includes an output generating a signal corresponding to the comparator output. The integrated circuit includes a monitor circuit. The monitor circuit is coupled to the output of the detection circuit and determines whether the voltage state of the cell transitions between application of the read and margin voltages to the gate.

Electronic circuit and method for testing and refreshing non-volatile memory

An electronic circuit includes a non-volatile memory that has several memory cells. The output of the non-volatile memory is connected to the inputs of several latches. Each latch has an output adapted to be read independently. A refresh circuit is connected to address lines of the non-volatile memory and to the write pins of each of the latches. The data contained in the memory cells of the non-volatile memory is represented by the data contained in the latches.

Electronic circuit and method for storing configuration and calibration information in a non-volatile memory array

A current compensating bias generator generates a current which follows voltage. The current compensating bias generator has a bias generator circuit for generating a current. A current compensating circuit is coupled to the bias generator circuit for changing a value of the current as a voltage input to the current compensating bias generator is changed. A resistive ladder circuit is coupled to the current compensating circuit for setting a voltage level trip point for the current compensating circuit at which the current compensating circuit is used to change the value of the current.

Current compensating bias generator and method therefor

A voltage compensated oscillator circuit having a resistor capacitor (RC) circuit for setting a frequency of oscillation for the oscillator circuit. A switching circuit with hysterisis is coupled to the RC circuit for providing upper and lower threshold limits. The upper and lower threshold limits being used for controlling the direction of switching of the oscillator circuit. By adjusting the upper and lower threshold limits, one may compensate for voltage signal fluctuations so that the frequency of oscillation will not change due to power supply voltage fluctuations.

Voltage compensated oscillator and method therefor

An improved reprogrammable memory device permits definition of a page within an array of memory cells which is variable in size, erasure of only that data contained within the defined variable page while uneffecting the remaining data in the array of memory cells and reprogramming the defined variable page. The improved reprogrammable memory device with variable page size comprises an array of memory cells where the memory cells are arranged in rows and columns; address decode logic coupled to the array of memory cells for accessing the array of memory cells; amplifier logic coupled to the array of memory cells for amplifying the voltage levels between a plurality of the memory cells and data bus when accessing the array of memory cells; column select logic coupled to the array of memory cells for determining which word from a selected row of the array of the memory cells is accessed and for connecting the plurality of memory cells to the amplifier logic; control signals coupled to the amplifier logic for accessing the array of memory cells; and, block enable signals coupled to the address decode logic for varying page size within the array of memory cells to be erased.

Reprogrammable memory device with variable page size

A progressive start-up charge pump that eliminates the start-up problems of p-channel charge pump stages by starting the charge pump one stage at a time. The charge pump has a plurality of charge pump stages wherein each of the plurality of charge pump stages are coupled to a successive charge pump stage in a cascade mode. An enabling circuit is coupled to each of the plurality of charge pump stages for individually starting each of the plurality of charge pump stages one charge pump stage at a time starting with a last charge pump stage and successively turning on a directly previous charge pump stages until the first charge pump stage is started. This will ensure that the voltage output node is at a greater potential than the voltage input node for each of the plurality of charge pump stages during start-up.

Progressive start-up charge pump and method therefor

A zero-current start-up circuit for a reference circuit which is initially unbiased and which has internal nodes that needs to be regulated to a predetermined voltage. When the start-up circuit is enabled, a switching transistor is turned on which enables the reference circuit to generate an internal reference current which regulates an output current to a predetermined value set by the reference circuit. The output current flows through a voltage drop device and when the voltage level reaches a predetermined value, the start-up circuit is disabled eliminating the current path.

Zero-current start-up circuit

An I/O holdoff mechanism is used to compensate for I/O device inputs being fed through a latency introducing bus. A system includes one or more I/O devices connected through a serial bus to a controller device. Each I/O device includes at least one request pin which is connected to a peripheral device. A serializer in the I/O device responds to a voltage transition occurring on any request pin of the I/O device by forwarding, in a packet over the serial bus, an indicator. The indicator indicates a current voltage on the request pin of the I/O device on which the voltage transition occurred. The controller device includes a deserializer and a bus controller. The deserializer receives the first packet and outputs a signal which indicates a current value for the voltage on the indicated request pin. The deserializer includes a busy output which indicates when the deserializer is busy and when the deserializer is idle. The bus controller responds to a request from a host system for a current value on a first request pin of the I/O device by forwarding to the host system a current value for a voltage on the indicated request pin, as indicated by the deserializer, when the deserializer is not busy. When the deserializer is busy, the bus controller responds to the request from the host system for the current value on the first request pin of the I/O device by waiting for the deserializer to become idle. Upon the deserializer becoming idle, the bus controller forwards to the host system the current value for the voltage on the indicated request pin.

Input/output (I/O) holdoff mechanism for use in a system where I/O

A computing system encodes and emulates requests signals, such as DMA requests or interrupt requests. A first peripheral device is connected to a first request pin of a first input/output (I/O) device. When the first peripheral device asserts a first request signal on the first request pin, a serializer within the first I/O device generates a first packet. The serializer forwards the first packet to a serial out port of the first I/O device. The first packet identifies the type of request and the direction of the edge transition. The serial out port forwards the first packet to a serial in port of a controller device. Upon the serial in port receiving the first packet, an unserializer within the controller device asserts an emulated first request signal, the emulated first request signal being coupled to a first request controller within the controller device. When the first peripheral device de-asserts the first request signal on the first request pin of the first I/O device, the serializer generates a second packet. The second packet identifies the type of request and the direction of the edge transition. The serializer forwards the second packet to the serial out port of the first I/O device. The serial out port of the first I/O device forwards the second packet to the serial in port of the controller device. Upon the serial in port receiving the second packet, the unserializer within the request controller de-asserts the emulated first request signal. When the first peripheral device pulses the first request signal by quickly de-asserting and asserting the first request signal in quick succession, the second packet is sent, but not the first packet.

Encoding assertion and de-assertion of interrupt requests and DMA

A single bit status register includes an input flip-flop, an asynchronous latch having an input coupled to an output of the input flip-flop, a comparator for comparing the outputs of the flip-flop and the latch, and an output stage which provides an error output when the comparator determines that the outputs of the flip-flop and the latch are not the same. In this fashion, it is known when a 'read' of the status register is invalid due to the presence of the error output. Preferably, the register also includes a reset disabling mechanism which prevents the input flip-flop from being reset until a valid read has occurred. A n-bit status register includes n register sections, where each register section includes an input flip-flop, an asynchronous latch having an input coupled to an output of the input flip-flop, and a register section comparison mechanism for comparing the outputs of the flip-flop and the latch in that register section. The method of the present invention includes the steps of: a) capturing a status bit in an input flip; b) latching the status bit into an output latch; c) asynchronously enabling the output latch; d) comparing the outputs of the flip-flop and the latch; e) outputting an error signal if the outputs of the flip-flop and the latch are different; and f) outputting the status bit at least if the output of the flip-flop and the latch are the same.

Growing community of inventors

Gilbert, AZ, United States of America

Joseph Alan Thomsen