Digital Design
Errata and Clarifications
-------------------------

Although we exerted tremendous effort to ensure this first edition
book would not contain errors, a few errors may still manage
to slip by. Below are mistakes found. Many thanks to the students and 
teachers who found them. Report errors to vahid@cs.ucr.edu.

Chapter 2
   EXERCISES
   * Page 93, Exercise 2.66 -- We do not presently know of a solution
     to this problem. The circuit in the solutions manual is not a correct 
     solution to the stated problem. (Thank you to Greg Link of York 
     College of Penn., 9/07)

---------


Chapter 3
---------
   * Page 106, Fig 3.24: In the timing diagram, Qm/Ds should return to
       0 when Clk returns to 0, because D/Dm is 0 at that time. Presently,
       Qm/Ds is shown as staying at 1. This change does not impact the 
       the main point of the example, namely the value of Qs.
       (Thank you to Mark Brehob of Univ. of Michigan, 5/07)
   * Page 101, Fig 3.15: In the timing diagram, R1 should be 0 from the
     beginning. (Thank you to Jose J. Farrington and Rafael Arce Nazario, 
     University of Puerto Rico - Rio Piedras, 10/08)


Chapter 4
---------
   * Page 152: Fig 4.2 -- the four wires going to I3,I2,I1,I0 of R2 
        should be reversed. For example, R0's Q0 output should go through 
        the inverter to I0 rather than to I3.
       (Thanks to Mahamed G. H. Omran of Gulf Univ. for Science and 
        Technology in Kuwait).  
   * Page 168:     S = a'(b xor c)' + a(b xor c)
       should be:  S = a'(b xor c)  + a(b xor c)'
       (Thank you to Mark Brehob of Univ. of Michigan, 5/07)


Chapter 5
---------
   * Page 227, Example 5.1: Although not explicitly stated, we assume that 
     the separation between two coins is very long compared to clock cycles.
     We also assume that the 8-bit input "a" continues to indicate the coin 
     value for a long time (many clock cycles) after input "c" pulses. 
     (Thank you to Mark Brehob of Univ. of Michigan, 5/07)
   * Page 246, Fig 5.32: The bottom-left arrow, from R in state A to
     Q in state B, should be deleted, because the assignment Q=R was moved
     to state B. The main point of the figure is still correct, but the
     extra arrow suggests a transfer that does not occur.
     (Thank you to Prof. Mahamed G. H. Omran of
     Gulf University for Science & Technology, 5/2010).

   * Page 290: The sentence "how to write a 9 and a 13 into locations
     500 and 999" should be "how to write a 500 and a 999 into
     locations 9 and 13"
     (Thank you to Prof. Mahamed G. H. Omran of
     Gulf University for Science & Technology, 5/2010).



Chapter 6
---------
   * Page 357, first paragraph: The sentence that says "If the content's
     value is less than 128, then we know..." should have said "GREATER than
     the KEY" rather than "less than 128." We compare the contents with
     the key while trying to find the key, not with the address. Also,
     for the binary search as described, it should be clear that the sorting 
     of items should be in ascending order, and thus, when the contents are
     greater, we need to look in 0 to 127. Likewise, for the next comparison,
     "If the value there is less than the key, we search 0 to 63; if greater,
     we search 65-127," the "less" should be "greater," and the "greater"
     should be "less". (Thank you to Anatolio Laschuk 
     Porto Alegre in Brazil).