CONFIG_ISA_THUMB2

(No prompt – not directly user assignable.)

Type: bool

Help

From: http://www.arm.com/products/processors/technologies/instruction-set-architectures.php

Thumb-2 technology is the instruction set underlying the ARM Cortex architecture which provides enhanced levels of performance, energy efficiency, and code density for a wide range of embedded applications.

Thumb-2 technology builds on the success of Thumb, the innovative high code density instruction set for ARM microprocessor cores, to increase the power of the ARM microprocessor core available to developers of low cost, high performance systems.

The technology is backwards compatible with existing ARM and Thumb solutions, while significantly extending the features available to the Thumb instructions set. This allows more of the application to benefit from the best in class code density of Thumb.

For performance optimized code Thumb-2 technology uses 31 percent less memory to reduce system cost, while providing up to 38 percent higher performance than existing high density code, which can be used to prolong battery-life or to enrich the product feature set. Thumb-2 technology is featured in the processor, and in all ARMv7 architecture-based processors.

Direct dependencies

!ARM64 && ARM

(Includes any dependencies from ifs and menus.)

Defaults

No defaults. Implicitly defaults to n.

Symbols that select this symbol

• ARMV6_M_ARMV8_M_BASELINE

• ARMV7_M_ARMV8_M_MAINLINE

• ARMV7_R

Kconfig definition

At <Zephyr>/arch/arm/core/aarch32/Kconfig:35

Included via <Zephyr>/Kconfig:8 → <Zephyr>/Kconfig.zephyr:29 → <Zephyr>/arch/Kconfig:12 → <Zephyr>/arch/arm/Kconfig:42

Menu path: (Top) → ARM Options

config ISA_THUMB2
    bool
    depends on !ARM64 && ARM
    help
      From: http://www.arm.com/products/processors/technologies/instruction-set-architectures.php

      Thumb-2 technology is the instruction set underlying the ARM Cortex
      architecture which provides enhanced levels of performance, energy
      efficiency, and code density for a wide range of embedded
      applications.

      Thumb-2 technology builds on the success of Thumb, the innovative
      high code density instruction set for ARM microprocessor cores, to
      increase the power of the ARM microprocessor core available to
      developers of low cost, high performance systems.

      The technology is backwards compatible with existing ARM and Thumb
      solutions, while significantly extending the features available to
      the Thumb instructions set. This allows more of the application to
      benefit from the best in class code density of Thumb.

      For performance optimized code Thumb-2 technology uses 31 percent
      less memory to reduce system cost, while providing up to 38 percent
      higher performance than existing high density code, which can be used
      to prolong battery-life or to enrich the product feature set. Thumb-2
      technology is featured in the  processor, and in all ARMv7
      architecture-based processors.

(The ‘depends on’ condition includes propagated dependencies from ifs and menus.)