I'm trying to code a way to add specific halfwords from word-sized numbers in the ARM assembly language. For example, lets say I want to add the first 4 digits of r0=0x3B029BA1 and r1=0x0B54A361 or the middle 4 digits of r0=0x3B029BA1 and r1=0x0B54A361. I can't seem to make this work. This is a shortened example of what I have so far.
LDR r0, =0x3B029BA1; LDR r1, =0x0B54A361; LDRH r10, [r1];
I'm pretty sure there will need to be an offset for the address in the 3rd line of the code, but I haven't gotten past a halfword just getting into the register 10. Every time I run this code, the correct register values end up in r0 and r1, but nothing at all is appearing in r10. So before I do anything else, I just want to understand why this is happening.