Using AVR assembly language, write a subroutine XOR that evaluates the logical exclusive-OR of two operands A and B. The subroutine will be implemented using a skeleton code shown below: ORG 0x000F RCALL XOR .ORG 0x100F XOR: i Your code goes here RET (a) Assume the value A is in R1 and value B in R2 when the subroutine is called. However, there is a catch! You can use any AVR assembly instructions except EOR and AND instructions. In addition, you may not destroy (overwrite) the original contents of registers RI and R2 (b) Show the contents of the stack right after RCALL is made