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.
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.
Interrupt servicing after longjmp instruction

I'm using Keil compiler for 8051Warp uP. I would like to make a jump from an interrupt routine back to the main function, this way: main () { init_function(); if (setjmp(env)!=0) { //...
C51 compiler interrupt routine instructions.

Hello all, I have been PIC controller for a while, I am now looking forward to learn more about. I have downloaded the Eval kit of Keil (C51), but I don't seem to find informative instructions on Eval...
Interruptible-restartable instructions and Others

Hi, As I have found in: Cortex-M0+ Devices Generic User Guide: 2.1.3. Core registers There is information about instruction behaviour during interrupts: "Interruptible-restartable instructions The interruptible...