I am having trouble changing the endian of a variable.

First, I have two bytes that I want to combine to form a short. I have been able to do this by:

s = (b1 * 256) + b2;

Now, I want to swap all of the bits so that "s" that initially equals:

1100000000000010

becomes

0100000000000011

I would like to do it "simpler" than a line of code per bit if possible....

When developing with our Astrobe Oberon language system you can use the SYSTEM function RBIT to reverse all the bits in a word. e.g.

s := SYSTEM.RBIT(s);

It generates a single inline Cortex-M3 instruction to perform the operation.

If you are programming in C the most efficient way would be to implement it as an inline assembly language call to use the corresponding RBIT instruction.

Regards, Chris Burrows CFB Software http://www.astrobe.com

One addition to Chris' answer: There is no need to add an inline assembly call yourself, just use the C-function:

uint32_t __RBIT(uint32_t value) 

That will insert the required assembly for you.