Dallas Semiconductor Corporation

Frank V Taylor, Iii

Stephen N Grider

Edward Tang Kwai Ma

Wendell L Little

Edward Tangkwai Ma

Joseph P Gorski

Andrew D Jones

Ann Little

Sai Bun Samuel Wong

Methods, systems, and arrangements enable efficient reprogramming of a memory block of a microcontroller. Two blocks of memory each have a different logical location with respect to a processor of the microcontroller. The first memory may store vector information to be executed by the processor. The second memory may store data information. The logical location of each memory block is dependent on the value of a pre-determined bit in a specified register. When a user wishes to reprogram the contents of the first memory, the user enters new code into the second memory. Upon completion, the value of the pre-determined bit is changed, and the logical locations of the first and second memories are interchanged. In effect, the newly entered code from the second memory is accessed as if it were in the first memory (e.g., from an addressing perspective), and the processor may execute the new program (e.g., after the processor undergoes a system reset).

Memory exchange

The present invention provides an 8-bit microcontroller capable of supporting expanded addressing capability in one of three address modes. The microcontroller operates in either the traditional 16-bit address mode, a 24-bit paged address mode or in a 24-bit contiguous address mode based on the setting of a new Address Control (ACON) Special Function Register (SFR). The 24-bit paged address mode is binary code compliant with traditional compilers for the standard 16-bit address range, but allows for up to 16M bytes of program memory and 16M bytes of data memory to be supported via a new Address Page (AP) SFR, a new first extended data pointer (DPX) SFR and a new second extended data pointer (DPX ) register. The 24-bit contiguous mode requires a 24-bit address compiler that supports contiguous program flow over the entire 24-bit address range via the addition of an operand and/or cycles to either basic instructions.

Method and apparatus for 24-bit memory addressing in microcontrollers

A microcontroller integrated circuit incorporating a user configurable pulse width modulator. The pulse width modulator circuitry is configurable to be a single, for example 32-bit pulse width modulator, or a plurality of pulse width modulators each having a bit width that is divisible by the single 32-bit pulse width modulator (e.g., 2, 4, 8 or 16-bit pulse width modulators).

Microcontroller with a user configurable pulse width modulator

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Highland Village, TX, United States of America

Frank V Taylor, Iii