Microprocessor — DU B.Sc. (Hons) Physics Previous Year Question Papers

2. Attempt Four questions in all. (a) Explain the difference between machine language and the assembly language of the 8085 microprocessor. (b) Classify the instructions in terms of their word size, with example. (c) What are general-purpose registers in 8085 microprocessor. (d) Write instructions to load the two hexadecimal numbers 32H and 48H in registers A and B respectively. Add the numbers, , and display the sum at the output port PORTI. (e) How does a Microprocessor differentiate between data and instruction code? (f) What are machine control instructions? Give two examples. Q.2 (a) Identify the opcodes and operands.in the following instructions. Show order of entering the codes in memory. (b)What is memory map? How many memory locations can be (5) addressed by a microprocessor with 14 address lines? (c) Briefly explain all the control and status signals in 8085 (a) Tabulate the status and control signals (Truth table for 1O/M,S1, (9) SO and control signals) for the machine cyclés:Opcode fetch, Memory Read, Memory Write, /O Read, 1'0 write Interrupt Acknowledge, Halt, Hold and Reset (b) Illustrate the steps and timing diagram when the instruction code (6) 4FH- MOV C,A) stored in location 200SH is being fetched. (a) Explain demultiplexing of the bus ADT-ADO, with a schematic (6) diagram. Explain the function of latch and ALE signal in demultiplexing. (b) If the clock frequency is 5 MHz, how much time is required to execute an instruction of 18 T-states? (c) The memory location 2050H holds the data byte F7H. Write (6) instructions to transfer the data byte to the accumulator using three different opcodes: MOV, LDAX and LDA. Specify the addressing mode and briefly explain the execution of these in terms of registers used. (a) Explain the function of machine control instructions HLT and NOP (3) Criy expie their anting modes of the flowing instructions and (4) (c) Sixteen bytes of data are stored in memory locations at 2050H to 20SFH. Transfer the entire block of data to new memory locations starting at 2070H. (8)