Книга: Advanced PIC Microcontroller Projects in C

2.3 Exercises

2.3 Exercises

1. Describe the data memory structure of the PIC18F452 microcontroller. What is a bank? How many banks are there?

2. Explain the differences between a general purpose register (GPR) and a special function register (SFR).

3. Explain the various ways the PIC18F microcontroller can be reset. Draw a circuit diagram to show how an external push-button switch can be used to reset the microcontroller.

4. Describe the various clock sources that can be used to provide a clock to a PIC18F452 microcontroller. Draw a circuit diagram to show how a 10MHz crystal can be connected to the microcontroller.

5. Draw a circuit diagram to show how a resonator can be connected to a PIC18F microcontroller.

6. In a non-time-critical application a clock must be provided for a PIC18F452 microcontroller using an external resistor and a capacitor. Draw a circuit diagram to show how this can be done and find the component values for a required clock frequency of 5MHz.

7. Explain how an external clock can provide clock pulses to a PIC18F microcontroller.

8. What are the registers of PORTA? Explain the operation of the port by drawing the port block diagram.

9. The watchdog timer must be set to provide an automatic reset every 0.5 seconds. Describe how to do this, including the appropriate register bits.

10. PWM pulses must be generated from pin CCP1 of a PIC18F452 microcontroller. The required pulse period is 100ms, and the required duty cycle is 50%. Assuming the microcontroller is operating with a 4MHz crystal, calculate the values to be loaded into the various registers.

11. Again, with regard to PWM pulses generated from pin CCP1 of a PIC18F452 microcontroller: If the required pulse frequency is 40KHz, and the required duty cycle is 50%, and assuming the microcontroller is operating with a 4MHz crystal, calculate the values to be loaded into the various registers.

12. An LM35DZ-type analog temperature sensor is connected to analog port AN0 of a PIC18F452 microcontroller. The sensor provides an analog output voltage proportional to the temperature (i.e., V0 = 10 mV/°C). Show the steps required to read the temperature.

13. Explain the difference between a priority interrupt and a nonpriority interrupt.

14. Show the steps required to set up INT2 as a falling-edge triggered interrupt input having low priority. What is the interrupt vector address?

15. Show the steps required to set up both INT1 and INT2 as falling-edge triggered interrupt inputs having low priority.

16. Show the steps required to set up INT1 as falling-edge triggered and INT2 as rising-edge triggered interrupt inputs having high priorities. Explain how to find the source of the interrupt when an interrupt occurs.

17. Show the steps required to set up Timer 0 to generate interrupts every millisecond with a high priority. What is the interrupt vector address?

18. In an application the CPU registers have been configured to accept interrupts from external sources INT0, INT1, and INT2. An interrupt has been detected. Explain how to find the source of the interrupt.

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