• Why does ARMSim# not recognize instruction 'addw'?
    Hi, For the below code, ARMSim# does not recognize '.arch armv7-r'. It says: "unknown opcode or directive: .arch"It does not recognize 'addw' either, says: "unknown opcode or directive: addw"I have check...
  • Branch and Call Sequences Explained
    What Does a Branch Do? A branch, quite simply, is a break in the sequential flow of instructions that the processor is executing. Some other architectures call them jumps, but they're essentially...
  • Is Thumb to ARM mode overhead
    Hi all, Consider high priority routines are executing in ARM mode and low priority in Thumb mode. There could be constant switching between ARM and THUMB mode. In this inter-working model is there any...
  • Question about a code snippet on ARM, Thumb state change
    Hi, I find the following code snippet online on ARM state change. Although that whole material looks solid, the second line in the blue code below is puzzling. add R1,PC,#1 ;Load address of SUB_BRANCH...
  • Why the different encodings?
    Why are there different encodings of instructions? What's the idea/background/etc for their co-existence? Can different encodings be mixed in the code? (Not ARM encodings with Thumb encodings- without...