1. The CALL and RET instruction. a How many bytes do CALL and RET instructions each have? b With each CALL instruction, is the stack pointer incremented or decremented, and by how much? c With each RET instruction, is the stack pointer incremented or decremented, and by how much?

2. Convert the following assembly code to binary by hand using the instruction table in the end of the 273 booklet. You must use the little endian in representing the low and high bytes at each program memory location.

FUN: LDI R16, 200

LDI R19, 15

BACK: LDI R18, 25

SUB R19, R18

HERE: NOP

DEC R18

INC R19

BRNE HERE

DEC R16

BRNE BACK

RET

3. Find the time delay of the above program if the system has an AVR with a frequency of 16MHz.