New lecture slides, and Midterm grades are online now.
Chapter 4 (slides), and assignment 4 are online now.
* The Midterm exam includes: Chapter 1,2,3, and Chapter 4 (Book: 4.1, 4.2 - Slides:to slide 40). * If you don't have enough time to read book "Chapter 4", don't worry. Reading the Slides, and doing "assignment 4" are enough to cover last lecture. * In the book, at the end of page 138 (pdf 109): Please correct the following sentence "The Carry flag is exclusive ORed with the high bit of the result" ---> "The Carry out is exclusive ORed with the Carry in for the highest bit of the result" Example: mov al, 1 sub al, 128 ; al=1000 0001 In this example, the actual carry out= 0. However, the x86 processor invert this value and state the carry flag, then CF=1. Meanwhile, the Carry in of MSB=1 in the result of this operation. Thus: if it's Carry flag xor MSB: then 1 xor 1 =0 (Wrong) if it's Carry out xor Carry In of MSB: then 0 xor 1= 1 (Correct) How it comes? 0000 0001 0000 0001 -1000 0000 ->+0111 1111 + 1 ------------------------------------ 1000 0001 CarryIn=1 CarryOut=0 Then CF=Inversion of CarryOut= 1 OF=CarryIn Xor Carryout=1 Add example: 0000 0001 +1111 1111 ----------------- 0000 0000 CarryIn=1 CarryOut=1 Then CF=1, OF=0 The new lecture and the Midterm grades are online now.
Assignment 3 II is online now.
If you already downloaded assignment 4, please neglect and complete Assignment 3 II. Tomorrow's (Thursday, 7th November) Lecture is canceled
Chapter 3 materials, and assignment 3 are online now.
Try to read Chapter 3 (book, slides). However, don't panic from the new contents\information within the materials, we are not done with chapter 3 yet. |
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