How to perform an Assembly code within a C program in Keil for ARM cortex M

Dr. Carlos Hernandez-Gutierrez.

This sample is to perform an Assembly code within a C program.
The function is for a delay routine, where the R0 loads the value of n parameter of Delay function.
Then R0 is decreased to 0 and Jump to Delay until R0 is 0.
The routine spends three machine cycles. Thus if the clock system is 80MHz the delay obeys to the following formula.

Delay = n * 3 (1/80Mhz)

/* ****************************************************************************/*
__asm void
Delay(unsigned long n)
{
            SUBS    R0, #1
            BNE     Delay
            BX      LR ; //the link register is providing the address to branch to.
}