Page 170 - DCAP210_INTRODUCTION__TO_MICROPROCESSORS

Introduction to Microprocessors

Notes JNZ Loop : Loop until reaches zero.

RST1 : Stop.
2. Calculate the total time required to execute the following delay subroutine.
Delay: LXI D,02F1h
Loop: DCX D

MOV A,E
ORA D JNZ
Loop RST1

11.10 Self-Assessment Questions

1. PC can be updated by making the enable signal high.

(a) True (b) False
2. ……… set up by loading a register with a certain value.
(a) INR (b) DCR

(c) Loop counter (d) None of the above
3. Harvard-based systems tend to store ……… machine word per memory location.
(a) one (b) two

(c) three (d) None of the above
4. The first instruction initializes the loop counter and is executed only once requiring only 7
T-States.

(a) True (b) False
5. The ……… required by each instruction is function of the number of T-states in itsinstruction
cycle.
(a) installation time (b) execution time
(c) process time (d) None of the above

6. Single register can repeat a loop for a maximum count of 205 times.
(a) True (b) False

11.11 Review Questions

1. What do you mean by loop counter?
2. Define PC.

3. Explain branching. and name its types.
4. Explain programmed time delays.
5. Define time delays.

6. Describe the steps to use register as a loop counter with example.
7. What are nested loops?
8. What do you mean by hexadecimal?

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