ece 109

Write the decimal value -35 using 8-bit 2's complement binary representation.

11011101

Which component of a von Neumann machine is responsible for storing long-term values used during computation?

Memory

Which component of a von Neumann machine is responsible for storing the instructions to be executed?

Memory

Suppose you have an ASCII character that you know to be a letter. But you don't know whether it is upper-case or lower-case. What is the best way to transform this character (if needed) into a lower-case character?

OR the original character with the value x20.

In LC-3 assembly language, PUTS is a symbol that represents TRAP x22. What does that service routine do?

Prints the string whose address is in R0.

Using 32-bit IEEE floating-point format, what is the binary representation of the decimal value 84.5?

01000010101010010000000000000000

Enter a single 16-bit LC-3 instruction (in binary) that sets the value of R4 to zero.

0101100100100000

Which component of a von Neumann machine is responsible for orchestrating the execution of instructions?

Control Unit

Put the steps of executing an instruction in the correct order.

fetch, decode, execute

Which two methods are used for managing transfer to/from an I/O Device?

polling, interrupts

The two types of mapping for the I/O Devices are:

I/O Mapped, Memory-Mapped

Considering the LC-3 datapath shown in Figure 3.3, which special-purpose registers are involved in the FETCH stage of executing an instruction?

IR, PC, MAR, MDR

Which component of a von Neumann machine is responsible for carrying out arithmetic or logical operations on data?

Processing Unit

Which component of a von Neumann machine is responsible for storing temporary values used during computation?

Processing Unit

Which of the following are NOT steps that are part of performing a LOAD operation? Select all that apply. Select one or more:

Read data from MAR., Write address into MDR, Read address from MAR, Write data into MDR,

Write a single 16-bit LC-3 instruction (in binary) that sets the condition code bits (N, Z, P) according to the value in R0, but does not change any register values. For example, if the current value in R0 is negative, then the N bit should be set after your instruction is executed. But the value in R0 (or any other register) must be unchanged.

0001000000100000

Enter a single 16-bit LC-3 instruction (in binary) that increments the value in R2 by 5.

0001010010100101

Write a single 16-bit LC-3 instruction (in binary) that doubles the value in R3.

0001011011000011

Enter a single 16-bit LC-3 instruction (in binary) that decrements the value in R3 by 10.

0001011011110110

Write a single 16-bit LC-3 instruction (in binary) that clears the least significant two bits of R5. In other words, after your instruction is executed, bits 0 and 1 of R5 will be zero, and the rest of R5 will be unchanged.

0101101101111100

Write a single 16-bit LC-3 instruction (in binary) that clears all the bits of R6 except the least significant two bits. In other words, after your instruction executes, bits 0 and 1 of R6 will be unchanged, and the rest of R6 will be zero.

0101110110100011

A 4-KB (kilobyte) memory has a 32-bit wordsize. How many address bits are required to access this memory? (Note that a kilobyte is 1024 bytes.)

10

Convert the decimal value 130 to unsigned binary representation.

10000010

Write the decimal value 82 using 8-bit 2's complement binary representation. (NOTE: Answer displayed by Moodle will not show leading zeroes. But you should include them in your answer.)

1010010

Convert the decimal value 43 to unsigned binary representation.

101011

A memory has a 256-bit wordsize. It is made up of 32 addressable locations. What is its total size, in bytes?

1024

Given an 5-bit two's complement binary number, what is the decimal value of the largest positive integer that can be represented?

15

What is the decimal value of the largest unsigned binary 8-bit integer?

255

A 2-KB (kilobyte) memory has a 64-bit wordsize. How many words can be stored in this memory? (Note that a kilobyte is 1024 bytes.)

256

In the LC-3, how many memory words are used to store the string below? (NOTE: The quotes are not part of the string.) "I want my...I want my...I want my MTV!"

39

Given the ASCII code of a digit character (e.g., '3'), what value should be subtracted to determine its numerical value (e.g., 3). Write the value in decimal (no # required) or hexadecimal.

48

With 6 bits, we can represent how many values?

64

If we want to represent 82 values, how many bits do we need?

7

In the LC-3, how many memory words are used to store the string "rainbow"?

8

An output from one CMOS gate cannot be used as the input to a different CMOS gate.

False

In a CMOS logic gate, an input signal of "0" turns a p-type transistor OFF. (NOTE: "OFF" means that the transistor acts like an open switch.)

False

In a CMOS logic gate, at least one n-type transistor and one p-type transistor must be turned ON for the gate to function correctly. (NOTE: "ON" means that the transistor acts like a closed switch, a short circuit.)

False

No current flows through a CMOS logic gate circuit, except when it is switching from one output state to another.

True

Put steps in order to describe what happens during a LOAD operation?

Write address into MAR, Send read to memory, read data from MDR

What are the largest positive and negative offsets that can be used in the BR instruction? (Answer in decimal.)

-256 - 255

Given an 7-bit two's complement binary number, what is the decimal value of the largest negative integer that can be represented? (By "largest negative", we mean the negative integer with the largest magnitude.)

-64

In a CMOS logic gate, an input signal of "0" turns an n-type transistor OFF. (NOTE: "OFF" means that the transistor acts like an open switch.)

True

In a CMOS logic gate, an n-type transistor must be between the output signal and ground (GND).

True

In a CMOS logic gate, each input signal must be connected to an n-type and a p-type transistor.

True

In a CMOS logic gate, the role of a p-type transistor is to pull the output signal up to "1".

True

In the LC-3, an instruction which is fetched is completely decoded and executed before the interrupts are checked and processed.

True