Study with the several resources on Docsity
Earn points by helping other students or get them with a premium plan
Prepare for your exams
Study with the several resources on Docsity
Earn points to download
Earn points by helping other students or get them with a premium plan
The instructions and problems for exam three of the computer engineering ece 2030 course during the fall 2007 semester. The exam covers topics such as memory systems, datapath elements, and microcode. Students are required to solve problems related to dram chips, barrel shifters, and state machines.
Typology: Exams
1 / 6
This page cannot be seen from the preview
Don't miss anything!
4 problems, 6 pages Exam Three 28 November 2007
Instructions: This is a closed book, closed note exam. Calculators are not permitted. If you have a question, raise your hand and I will come to you. Please work the exam in pencil and do not separate the pages of the exam. For maximum credit, show your work. Good Luck!
Your Name ( please print ) ________________________________________________
1 2 3 4 total
4 problems, 6 pages Exam Three 28 November 2007
Problem 1 (3 parts, 30 points) Memory Systems
Part A (12 points) Consider a 64Mbit DRAM chip organized as 2 million addresses of 32-bit words. Assume both the DRAM cell and the DRAM chip are square. The column number and offset concatenate to form the memory address. Using the organization approach discussed in class, answer the following questions about the chip. Express all answers in decimal (not powers of two).
number of columns
number of words per column column decoder required ( n to m )
type of mux required ( n to m ) number of address lines in column number number of address lines in column offset
Part B (10 points) Consider an two gigabyte memory system with 1 billion addresses of 16-bit words using a 16 million address by 8-bit word memory DRAM chip.
word address lines for memory system
chips needed in one bank
banks for memory system memory decoder required ( n to m )
DRAM chips required
Part C (8 points) Design a 16 million address by 8 bit memory system with four 8M x 4 memory chips. Label all busses and indicate bit width. Assume R/W is connected and not shown here. Use a bank decoder if necessary.
8M x 4
D D D D
ADDR
CS
8M x 4
D D D D
ADDR
CS
8M x 4
D D D D
ADDR
CS
ADDR
24
MSEL
D D D D
8M x 4
D D D D
ADDR
CS
D D D D
4 problems, 6 pages Exam Three 28 November 2007
Problem 3 (3 parts, 26 points) Microcode
Using the supplied datapath, write microcode fragments to accomplish the following procedures. Express all values, except memory addresses, in hexadecimal notation. Use ‘X’ when a value is don’t cared. For maximum credit, complete the description field. ∩ means bitwise logical AND. Use only registers 1 & 2.
Part A (12 points) 255 15 256
2 1 1 ⎟− ⎠
# X Y Z rwe im en
im va au en
-a /s
lu en
lf su en
st ld en
st en
r/ -w
msel description
1
2
3
4
5
Part B (9 points) Copy mem[1000] to mem[2000]. Use only registers 1 & 2 # X Y Z rwe im en
im va au en
-a /s
lu en
lf su en
st ld en
st en
r/ -w
msel description
1
2
3
4
Part C (5 points) Write a microcode sequence that exchanges R 1 and R 2. Use only registers 1, 2, & 3. # X Y Z rwe im en
im va au en
-a /s
lu en
lf su en
st ld en
st en
r/ -w
msel description
1
2
3
4 problems, 6 pages Exam Three 28 November 2007
Problem 4 (2 parts, 20 points) Sonny State Machine
Suppose you are designing a drought advisory state machine for the governor. It has two input signals:
S / R (which is 1 if the state of GA has had more mostly sunny days than rainy or cloudy days) and U / C (which is 1 if average water usage is above 100 gallons/person). There are three outputs:
Part A (14 points) Based on this state diagram, complete the state table below. S 1 S (^0) S / R U / C NS 1 NS 0 W E L 0 0 0 0 0 0 0 1 0 0 1 0 0 0 1 1 0 1 0 0 0 1 0 1 0 1 1 0 0 1 1 1 1 0 0 0 1 0 0 1 1 0 1 0 1 0 1 1 1 1 0 0 1 1 0 1 1 1 1 0 1 1 1 1 Part B (6 points) Give simplified Boolean expressions for the three outputs. Use the non-negated form of signals if they are available (e.g., use “R” instead of “not S” and “C” instead of “not U”).
W =. E =. L =.
