德爾福筆試（軟件類）

德爾福軟件方向的筆試題

１．How do you code an infinite loop in C?

2. Volatile：

a) What does the keyword volatile mean? Give an example

b) Can a parameter be both const and volatile? Give an example

c) Can a pointer be volatile? Give an example

3. What are the values of a, b, and c after the following instructions:

int a=5, b=7, c;

c = a+++b;

4, What do the following declarations mean?

a) const int a;

b) int const a;

c) const int *a;

d) int * const a;

e) int const * a const;

5. Which of the following statements describe the use of the keyword　static?

a) Within the body of a function: A static variable maintains its value　between function revocations

b) Within a module: A static variable is accessible by all functions　within that module

c) Within a module: A static function can only be called by other　functions within that module

6. Embedded systems always require the user to manipulate bits in　registers or variables. Given an integer variable a, write two code fragments.

The first should set bit 5 of a. The second shnuld clear bit 5 of a. In both　cases, the　remaining bits should be unmodified.

7. What does the following function return?

char foo(void)

{

unsigned int a = 6;

iht b = -20;

char c;

(a+b > 6)? (c=1): (c=0);

return c;

}

8. What values are printed when the following C program is executed?

int i = 8;

void main(void)

(

9. What will be the output of the following C code?

main()

{

int k, num= 30;

k =(num > 5? (num <=10? 100:200): 500);

printf("%d", k);

}

10. What will the following C code do?

int *ptr;

ptr =(int *)Ox67a9;

11. What will be the output of the follow C code?

main()

{

int i = 3, j, k;

j = product(i++);

k = product(++i);

printf("%d %d",j,k);

}

12. Simplify the following Boolean expression!((i ==12) || (j > 15))

13. How many flip-flop circuits are needed to divide by 16?

14. Provides 3 properties that make an OS, a RTOS?

15. What is pre-emption?

16. Assume the BC register value is 8538H, and the DE register　value is the value of register BC after the following　assembly operations:

MOV A,C

SUB E

MOV C,A

MOV A,B

SBB D

MOV B,A

the Assembly code shown below

LOOP: MVI C,78H

DCR C

JNZ LOOP

HLT

How many times is the DCR C Operation executed?

ribe the most efficient way(in term of execution time　and code size) to divide a number by 4 in assembly language