• UXTB only Thumb2?
    Note: This was originally posted on 12th February 2009 at http://forums.arm.com Hi All, Arm9 crashed on UXTB instruction because it is not able to decode it. It caused Undef-Instruction exception. I have...
  • Instruction width selection - forward/external reference
    Hi, I am learning the Thumb 2 instruction set and at the moment I am trying to understand when to use the instruction width specifier. e.g.: ldmia.w sp!,{r3,lr} I understand sometimes it is necessary...
  • M4 (Thumb2) to M0+ (Thumb) assembly language
    I have spent a long time trying to find the fastest ARM M0+ macros for C code but I am trying to write an M0+ processor and I have discovered that for an MP3 decoder, the processors ability is it's speed...
  • Cortex-M0 Thumb-2 instruction: Is this instruction valid?
    STM     r0!, {} I have looked at Thumb2 instruction set web but I can't find the behaviour of STM command if the reglist is empty. Thanks in advance.