Microchip Technology Inc.

Ryan Scott Ellison

Vivien Neil Delport

Joseph Harry Julicher

Sean Steedman

James B Nolan

Richard L Hull

Jerrold S Zdenek

Zacharias Marthinus Smit

Eric Schroeder

Hartono DArmawaskita

Scott Raymond Fink

Layton W Eagar

Gregory C Bingham

Michael S Pyska

James Clark Rogers

A microcontroller device has a central processing unit (CPU); a data memory coupled with the CPU divided into a plurality of memory banks, a plurality of special function registers and general purpose registers which may be memory-mapped, wherein at least the following special function registers are memory-mapped to all memory banks: a status register, a bank select register, a plurality of indirect memory address registers, a working register, and a program counter high latch; and wherein upon occurrence of a context switch, the CPU is operable to automatically save the content of the status register, the bank select register, the plurality of indirect memory address registers, the working register, and the program counter high latch, and upon return from the context switch restores the content of the status register, the bank select register, the plurality of indirect memory address registers, the working register, and the program counter high latch.

Context switching with automatic saving of special function registers memory-mapped to all banks

An n-bit microprocessor device has an n-bit central processing unit (CPU); a plurality of special function registers and general purpose registers which are memory-mapped to a plurality of banks, with at least two 16-bit indirect memory address registers which are accessible by the CPU across all banks; a bank access unit for coupling the CPU with one of the plurality of banks; a data memory coupled with the CPU; and a program memory coupled with the CPU, wherein the indirect address registers are operable to access the data memory or program memory and wherein a bit in each of the indirect memory address registers indicates an access to the data memory or to the program memory.

Enhanced microprocessor or microcontroller

A wake-up reset circuit is provided that generates a reset signal to a digital circuit upon a wake-up event. The wake-up reset circuit places the digital circuit into a known reset condition upon wake-up, even if a brown out condition occurs which may have caused unstable and unknown logic states in sequential circuit elements, e.g., volatile memory, flip flops and/or latching circuits. The wake-up reset circuit draws substantially no current when not generating the reset signal.

Wake-up reset circuit draws no current when a control signal indicates sleep mode for a digital device

Several calibration techniques for a precision relaxation oscillator with temperature compensation produces a stable clock frequency over wide variations of ambient temperature. The calibration techniques provide for different methods of determining CTAT current, PTAT current or the ratio of PTAT current to CTAT current. The calibration techniques provide different methods for determining CTAT and PTAT calibration values and for setting CTAT and PTAT calibration select switches.

Calibration techniques for a precision relaxation oscillator integrated circuit with temperature compensation

An oscillator with temperature compensation produces a stable clock frequency over wide variations of ambient temperature, and it includes an oscillation generator, two independent current generators, a transition detector and a clock inhibitor. The outputs of the two programmable, independent current generators are combined to provide a capacitor charging current that is independent of temperature. The oscillator is capable of three modes of operation: fast mode, slow/low power mode and sleep mode, which are controlled by the transition detector in response to external control signals. When the transition detector transitions from one mode to another, it controls the clock inhibitor to block a clock output of the oscillator generator for a predetermined number of clock cycles to allow the clock output to stabilize. The oscillator is implemented on a single, monolithic integrated circuit.

Oscillator with clock output inhibition control

The present invention relates to a microcontroller that may be configured to operate without the accompaniment of any external components. The microcontroller can function in a proper manner from the application of only power and signal lines with no external components required. The microcontroller has integrated internal reset and oscillator circuitry into the microcontroller. The microcontroller has also integrated simple external components such as current limiting resistors and pull u and pull down resistor into the microcontroller in order to avoid application specific external components.

Microcontroller having a minimal number of external components

The present invention relates to a configurable IC device pin. The IC device pin may be a device clock input pin or a digital I/O pin in one embodiment of the present invention, or a reset pin or a digital I/O pin in another embodiment of the present invention. Both embodiments of the present invention use a memory device to store information to configure the IC device pin. Input/Output logic is also used in both embodiments in order to transfer data to and from the IC device pin when the IC device pin is configured as a digital I/O pin.

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Chandler, AZ, United States of America

Ryan Scott Ellison