Ecet 340 week 1 homework

 

ECET340

 

 

 

 

 

Page 252, problem 1-5

 

 

 

1.Indicate what data type you would use for the following variables:

 

(a) The temperature           

 

(b) The number of days in a week            

 

(c) The number of days in a year             

 

(d) The number of months in a year          

 

(e) The counter to keep the number of people getting on a bus    

 

(f) The counter to keep the number of people going to a class     

 

(g) An address of 64K RAM space          

 

(h) The age of a person                             

 

(i) A string for a message to welcome people to a building          

 

 

 

2.Give the hex value that is sent to the port for each of the following C statements:

 

(a) PORTB=14;                 

 

(b) PORTB=0x18;            

 

(c) PORTB=′A′;               

 

(d) PORTB=7;                  

 

(e) PORTB=32;                 

 

(f) PORTB=0x45;           

 

(g) PORTB=255;              

 

(h) PORTB=0x0F;         

 

 

 

3.Give two factors that can affect time delay code size in the HCS12 microcontroller.

 

         

 

 

 

4.Of the two factors in Problem 3, which can be set by the system designer?

 

          

 

 

 

5.Can the programmer set the number of clock cycles used to execute an instruction? Explain your answer.

 

. 

 

 

 

Page 430-431, problem 1-9, 21-25

 

 

 

1.The LCD discussed in this section has ____ (4, 8) data pins.

 

2.Describe the function of pins E, R/W, and RS in the LCD.

 

 

 

 

 

3.What is the difference between the V_CC and V_EE pins on the LCD?

 

        

 

 

 

4.“Clear LCD” is a __ (command code, data item) and its value is __ hex.

 

 

 

5.What is the hex value of the command code for “display on, cursor on”?

 

    

 

 

 

6.Give the state of RS, E, and R/W when sending a command code to the LCD.

 

          

 

7.Give the state of RS, E, and R/W when sending data character ‘Z’ to the LCD.

 

           

 

 

 

8.Which of the following is needed on the E pin in order for a command code (or data) to be latched in by the LCD?

 

(a) H-to-L pulse

 

(b) L-to-H pulse

 

9.True or false. For the above to work, the value of the command code (data) must already be at the D0–D7 pins.

 

           

 

 

 

 

 

21. In reading the columns of a keyboard matrix, if no key is pressed we should get all ___ (1s, 0s).

 

 

 

22. In Figure 12-6, to detect the key press, which of the following is grounded?

 

 

 

      

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

23.In Figure 12-6, to identify the key pressed, which of the following is grounded?

 

 

 

         

 

 

 

 

 

24.Indicate the steps to detect the key press.

 

        

 

25.Indicate the steps to identify the key pressed.