1. ITEC 352 Lecture 14 ISA(6)

2. Review Questions? Beginning / End Memory locations Variable / Memory syntax PSR Loops / Branches

3. ISA(6) More assembly What does the program I show you do? How important are comments in assembly? How would we write a JAVA program that would produce similar assembly? What are the benefits / downsides of each approach to writing the software? Why are the memory locations offset by 4?

4. ISA(6) Conditionals ba –Always branch bne –Brach when Z is not 0 be –Branch when Z is 0 bg /bge ble –Branch when not (Z or (N xor V)) bpos / bneg –Branch when negative bit is on or off bv(c/s) –Overflow bit cleared or set How would you use these conditionals?

5. ISA(6) Jumping call –Goto a specific label in the program (memory where label is must be within 30 bits of the call statement) –Saves location of where call is in %r15 jmpl –Goto a specific address and store the location of the jmpl in %r15

6. ISA(6) Shifty Shift right (srl) –Shift a register by a certain % of bits and store the result in another register (0s are padded) –Syntax? Shift left (sll) –Instead of the right, go left Why is shifting bits important?

7. ISA(6) Summary Assembly instructions / simple program