TM4C1294NCPDT: Use of ARM THUMB-2 instruction set

Hello Salman

This is a CCS compiler question.

Salman Khan said:

"Additionally,
these microcontrollers use ARM's Thumb®-compatible Thumb-2 instruction set to reduce memory
requirements and, thereby, cost"

now i want to know how i can reduce memory requirements by using this feature??

You fell for a marketing euphemism.

Actually, you cannot 'un-use' this 'feature', Cortex M controller can only execute Thumb/Thumb-II instructions. They are hard-faulting when coming across an ARM instruction. ARM instructions are the 'long', faster variant, supported by Cortex A etc.

Thank you so much sir for your reply,

#1
i have read somewhere that
"
ARM Core has two execution states –ARM and Thumb
–
Switch between them using BX instruction
"
#2
and then i came across with the keyword "asm" (to write inline assembly code in c)
for e.g
int main()
{

asm("some BX instruction(to switch to thumb-2 instruction)");

}

Is this a way? , or it is automatically done by the compiler every time i write a code and build it.??

Salman Khan said:

i have read somewhere that
"
ARM Core has two execution states –ARM and Thumb

But the Cortex M core has not. It only supports Thumb. The core will hardfault if you try to execute an ARM (non - Thumb-II) instruction.

Check the arm.infocenter.com website for Cortex M4 technical reference manuals.