软件专业学生笔试题

软件专业学生笔试题

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

　　2. what value is stored in m in the following assembly language code fragment if n=7?

　　LDAA #n

　　LABEL1: CMPA #5

　　BHI L3

　　BEQ L2

　　DECA

　　BRA L1

　　LABEL2: CLRA

　　LABEL3: STAA #m

　　3. What is the state of a process if a resource is not available?

　　#define a 365*24*60*60

　　4. Using the #define statement, how would you declare a manifest constant that returns the number of seconds in a year? Disregard leap years in your answer.

　　5. Interrupts are an important part of embedded systems. Consequently, many compiler vendors offer an extension to standard C to support interrupts. Typically, the keyword is __interrupt. The following routine (ISR). Point out problems in the code.

　　__interrupt double compute_area (double radius)

　　{

　　double area = PI * radius * radius;

　　printf(“\nArea = %f”, area);

　　return area;

　　}