Answer the following problems

problem 1)a) In addition to data transfer operation, mention and describe the different functions supported by the instruction set of normal general purpose processors/microcontrollers. Give relevant exs for each category.

b) Mention the important points to be considered while interfacing external memory to processor/controller. Also describe the steps involved in interfacing.    

c) Describe in brief the architecture of PIC16F877 microcontroller.    

problem 2)a) With the help of a relevant diagram, describe the long distance communication between two computer terminals via telephone lines, using MODEMs. Describe clearly the functions of associated handshake signals.    

b) With the help of a relevant timing diagram, describe the ISA bus protocol for memory mapped I/O read operation with no wait states.    

c) Describe USB bus specifications and protocol with respect to serial communication in embedded systems.

problem 3) For the ADC section of 68HC11 microcontroller, Vref pin is connected to 5V and Gnd pin is grounded. After a certain analog input is converted to digital, the contents of ADRESULT _HI and ADRESULT _LO were found to be F7H and 86H respectively. Determine the analog input value and the channel to which the analog input was applied.

b) What do you mean by watchdog timer? What are the merits and demerits of using watchdog timer facility? Describe the working of watchdog timer facility of PIC16F877 microcontroller.    

c) With the help of a relevant diagram, describe the daisy chain arbitration scheme with respect to handling multiple interrupt requests from peripherals via a single interrupt line of the processor.