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 is a superset of the Thumb instruction set. Thumb-2 introduces 32-bit instructions that are intermixed with the 16-bit instructions. The Thumb-2 instruction set covers almost all the functionality of the ARM instruction set. Thumb-2 is backwards compatible with the ARMv6 Thumb instruction set. ARM Instruction Set Quick Reference Card ARM architecture versions Condition Field n ARM architecture version n and above Mnemonic Description Description (VFP) nT, nJ T or J variants of ARM architecture version n and above EQ Equal Equal 5E ARM v5E, and 6 and above NE Not equal Not equal, or unordered T2 All Thumb-2 versions of ARM v6 and We have mentioned above, all instructions in ARM processor are 32-bit or 16-bit aligned, so the LSB can be used as an indicator of instruction set. If the LSB is 1, the processor switches to Thumb state, and the actual target address is (*(PC) - 1), as the processor plus 1 to indicate the Thumb instruction state. Trophy points. 1,308. Activity points. 3,482. ARM = 32-bit instructions. Thumb = 16 bit instructions. Better performance / bigger code size in ARM mode vs Thumb. Thumb 2 is mixed 32/16 bit instructions. Somewhere in between the two. instruction set - primarily to increase code density - also increases performance in some cases It is not a complete architecture all 'Thumb-aware' cores also support the ARM instruction set - therefore the Thumb architecture need only support common functions SAN JOSE, Calif. — ARM Holdings plc has introduced Thumb-2, an instruction set for ARM processors which sits between the full ARM 32-bit instruction set architectures (ISAs) and the Thumb ISA which uses only a 16-bit instruction format, thereby saving memory space and power. Although Thumb-2 is a hybrid that includes both 16- and 32-bit The Thumb instruction set Outline: Îthe Thumb programmers' model • Thumb instructions • Thumb implementation • Thumb applications ©2001 PEVEIT Unit - ARM System Design Thumb - v4 - 2 What is Thumb? Thumb is: • a compressed, 16-bit representation of a subset of the ARM instruction set - primarily to increase code density Important Information for the Arm website. This site uses cookies to store information on your computer. By continuing to use our site, you consent to our cookies. The following sections details the subset of the ARM Thumb-2 instruction set supported by MicroPython. 1. Register move instructions 2. Load register from memory 3. Store register to memory 4. Logical & Bitwise instructions 5. Arithmetic instructions 6. Comparison instructions 7. Branch instructions 8. Stack push and pop 9. The Thumb instruction set provides most of the functionality required in a typical application. Arithmetic and logical operations, load/store data movements, and conditional and unconditional branches are supported. Based upon the available instruction set, any code written in C could be executed successfully in Thumb state. ARM mixes 16-, 32-bit instructions in Thumb-2 Richard Ball ARM has updated its Thumb 16-bit microprocessor instruction set, allowing it to be used by operating systems and interrupts. Extra instructions in Thumb-2 can also be mixed with standard 32-bit instructions, said the firm. Existing Thumb code has to be run in a different mode. ARM mixes 16