Ch9

Create an illustration depicting a computer architecture that represents the LC-3 system, showing registers, memory locations, and I/O operations with a modern, educational infographic style.

LC-3 I/O Operations Quiz

Test your knowledge of the LC-3 architecture and its I/O operations with this engaging quiz! From TRAP commands to the System Control Block, challenge yourself and see how well you understand the core concepts.

In this quiz, you will learn about:

The TRAP instruction and its functionalities
How the LC-3 handles I/O operations
Key registers and their roles in program execution

15 Questions4 MinutesCreated by LearningCoder971

The System Control Block or the Trap Vector Table is a set of memory locations which contain the starting addresses of the service routines.

True

False

The TRAP instruction stores the address of the instruction following the TRAP instruction in R0 before loading the PC with the starting address of the service routine.

True

False

In the LC-3, when a key on the keyboard is pressed, KBDR holds the 2's complement representation of that key.

True

False

The instruction TRAP x25 causes the PC to be loaded with the memory address:

x0025

X2500

the contents of x0025

X0250

The instruction TRAP x23 at location x4232, causes R7 to be loaded with:

X4232

X4233

contents of x4232

contents of x4233

In the LC-3, the clock is stopped by:

the STOP instruction

the instruction TRAP x25

the instruction TRAP x23

the END instruction

Which instruction in the LC-3 restarts the clock?

TRAP x30

RESTART

CLK_ST

No instruction can restart the clock.

What is wrong with the code fragment: .ORIG x3000 AND R0,R0, #0 AND R2,R2, #0 ADD R2,R2, #7 JSR SUB ADD R2,R2, ASCII ADD R0,R2,#0 TRAP x21 SUB ADD R2,R2,#9 ADD R7,R7,#1 RET ASCII .FILL x0030 .END

Nothing is wrong, the program outputs 16

We are modifying the contents of register R7. This destroys the linkage back to the calling program.

We are adding the x0030 (ascii code for 0), which is unnecessary.

TRAP x21 will not work after a subroutine call.

On execution of this program, the user inputs two numbers. Why do we need to add the value ASCII (xFFD0) to the numbers before adding them?

To strip off the ascii template, we need to add xFFD0 which is the negative of x0030 (ascii code for 0)

The program is wrong. It does not add correctly

To convert from hexadecimal to binary

The numbers are in 2's complement form

In the KBSR, an interrupt signal is generated by the AND of:

the start and stop bits

the ready bit and the interrupt-enable bit

the ready bit and the start bit

the start bit and the interrupt-enable bit

In the LC-3, the decision to opt for polling or interrupt driven I/O is made by the:

I/O device

Processor

Both of them

None of them

LC-3 I/O Operations Quiz

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