UNIT-1 MP&MC Two Marks EEE PDF

UNIT-1 MICROPROCESSOR ARCHITECTURE J.VIJAYA RAGHAVAN -AP/EEE , MVIT,Puducherry. EE T63 MICROPROCESSORS AND MICROCONTROLLERS UNIT I: MICROPROCESSOR ARCHITECTURE: 8085 Microprocessor architecture–Registers, Arithmetic and logic section, Timing and Control section and I...

UNIT-1 MICROPROCESSOR ARCHITECTURE J.VIJAYA RAGHAVAN -AP/EEE , MVIT,Puducherry. EE T63 MICROPROCESSORS AND MICROCONTROLLERS UNIT I: MICROPROCESSOR ARCHITECTURE: 8085 Microprocessor architecture–Registers, Arithmetic and logic section, Timing and Control section and Interface section-Machine cycles and bus timings– Wait states–Introduction to architecture of Z80 and MC6800 microprocessors. TWO MARKS 1.What is microprocessor? NOV 2013, APRIL/ MAY 2017 A microprocessor is a multipurpose, programmable logic device that reads binary instructions from a storage device called memory accepts binary data as input and processes data according to those instructions and provides result as output. 2. What are the basic units of a microprocessor? The basic units or blocks of a microprocessor are, ALU An array of registers Control unit. 3.List any two application of microprocessors.(April, 2011) 1. General purpose application i) Single board micro computers ii) Personal computers iii) Super minis and CDS 2. Special purpose application i) Instrumentation ii) Control iii) Communication iv) Office automation and publication 4.What is software and hardware? NOV 2013 Program A program is a sequence of instructions written to tell the computer to perform a specific function. DEPARTMENT OF ELECTRICAL AND ELECTRONICS ENGINEERING,MVIT ,PUDUCHERRY UNIT-1 MICROPROCESSOR ARCHITECTURE J.VIJAYA RAGHAVAN -AP/EEE , MVIT,Puducherry. Hardware: The physical components of a system are called hardware Software: A set of instructions written to perform a particular task is called a program, and a group of programs is called software. 5. What is an assembly language? An assembly language is a language which uses English – like words. Assembly language is microprocessor specific i.e programs written in assembly language are not transferable from one machine to another assembly language is machine dependent. Eg;8085 6. What is a low –level language? Low level language is a language which user the binary 0 and 1. All the microprocessor understands only the binary. 7. What is a high level language? Programming languages that are intended to be machine independent are high level languages. Instruction used in those languages is known as statements. Example: BASIC, C, C++ and Java 8. Define operating system? The interaction between the hardware and the software is managed by set of programs called an operating system of a computer, it overseas all the operation of the computer. 9. What is Microcomputer? It is a computer that is designed using a microprocessor as its CPU. It include microprocessor, memory and I / O (Input / Output). 10. What are the advantages of an assembly language in comparison with high level languages? The assembly language programs are compact and require less space. They are more efficient than the high – level language programs. 11. What are the advantages of high level language in comparison with the assembly languages.? The primary advantage of high – level language is in troubleshooting (debugging) programs. It is much easier to find errors in a program written in a high – level language than to find them in a program written in an assembly language. DEPARTMENT OF ELECTRICAL AND ELECTRONICS ENGINEERING,MVIT ,PUDUCHERRY UNIT-1 MICROPROCESSOR ARCHITECTURE J.VIJAYA RAGHAVAN -AP/EEE , MVIT,Puducherry. 12. Draw the block diagram of a microcomputer. It is possible to build the CPU on single chip, this came to be known as microprocessor.A computer with a microprocessor as its CPU is known as a microcomputer. 13. Define MPU The terms microprocessor and microprocessor unit (MPU) are often used synonymously. MPU implies a complete processing unit with the necessary control signals. Because of the limited number of available pins on a microprocessor package, some of signals (Such as control and multiplexed signals) need to be generated by using discrete devices to make the microprocessor a complete functional unit or MPU. 14. Name the types of buses in microprocessor. NOV 2017 Bus is a group of conducting lines that carries data, address and control signals. 1. address bus 2. Data bus 3. Control bus 15. Why is address bus unidirectional? APRIL/MAY 2017 The address is an identification number used by the microprocessor to identify or access a memory location or I/O device. It is an output signal from the processor. Hence the address bus is unidirectional. 16.Why data bus is bi-directional? NOV/DEC 2016 The microprocessor has to fetch(read) the data from memory or input device for processing and after processing it has to store(write) the data in memory or in output device.Hence the data bus is bidirectional. 17. What is the need of ALE signals m 8085processor? NOV/DEC 2016 ALE(Address latch enable) is a signal used to demultiplex the address and the data lines using an external latch. It is used as enable signal for the external latch. 18. How are the address and data lines demultiplexed in 8085? APRIL/MAY 2017, NOV/DEC 2016, NOV/DEC 2018 The data bus and the low order address bus on the 8085 microprocessor are multiplexed with each other. This allows 8 pins to be used where 16 would normally be required. The hardware interface is required to demultiplex the bus by latching the low order address in the first T cycle, on the falling edge of ALE. DEPARTMENT OF ELECTRICAL AND ELECTRONICS ENGINEERING,MVIT ,PUDUCHERRY UNIT-1 MICROPROCESSOR ARCHITECTURE J.VIJAYA RAGHAVAN -AP/EEE , MVIT,Puducherry. 19. Specify the size of data, address, and memory word and memory capacity of 8085 microprocessor. NOV/DEC 2016. Data bus has 8-bit data bus Address Bus 8085 has 16-bit address bus Word size of an 8085 microprocessor is 8-bit. Memory capacity − 8085 can access up to 64Kb. 20.Given the significance of a Microprocessor. (April,2015) The microprocessor is the master in the system, which controls all the activity of the system. It issues address and control signals and fetches the instruction and data from memory. Then it executes the instruction to take appropriate action. 21.Write the significance of control section in microprocessors. MAY 2019 It controls data flow inside the processor. It receives external instructions or commands to which it converts to sequence of control signals. It controls many execution units(i.e. ALU, data buffers and registers) contained within a CPU 22. List four operations commonly performed by the Microprocessor? NOV 2015 The various operations performed are Store 8-bit data Perform arithmetic and logical operations Test for conditions Sequence the execution of instructions Store data temporarily during execution in the defined R/W memory locations called the stack 23. Write the significance of Arithmetic and Logic section of a microprocessor. APRIL/MAY 2016. The ALU carries out the arithmetic and logic operations on 8-bit words. The contents of the accumulator and the temporary register are the inputs to the ALU. It can perform arithmetic operations such as addition, subtraction and logical operations such as AND, OR and EX-OR. The ALU result is then stored back in the accumulator. DEPARTMENT OF ELECTRICAL AND ELECTRONICS ENGINEERING,MVIT ,PUDUCHERRY UNIT-1 MICROPROCESSOR ARCHITECTURE J.VIJAYA RAGHAVAN -AP/EEE , MVIT,Puducherry. 24. What is the significance of general purpose registers in 8085? APRIL/MAY 2012 The 8085 has six general-purpose registers to store 8-bit data; these are identified as- B, C, D, E, H, and L. These can be combined as register pairs – BC, DE, and HL, to perform some 16-bit operation. These registers are used to store or copy temporary data, by using instructions, during the execution of the program. 25. Give the flag register format/bit pattern of 8085. MAY 2018, APRIL 2013. Sign flag, Zero flag, Auxiliary flag, Parity flag, Carry flag. 26. List and define the function of flags in 8085. APRIL/MAY 2017, APRIL/MAY 2012, NOV 2019, NOV/DEC 2018, NOV/DEC 2016. There are five flags in 8085. They are; Sign flag(SF) Zero flag(ZF) Auxiliary carry flag(AF) Parity flag(PF) Carry flag(CY) Sign flag(S): If D7is 0, sign flag is reset, which indicates a number is appositive number. Zero flag (Z): This flag is set to 1, if the ALU operation produces a result of 0.It is reset, if the result is not 0. Auxiliary carry flag (AC): In an arithmetic operation, when a carry is generated by digit D3 and passed on to digit D4, the AC flag is set. Parity flag(P): After an arithmetic or logical operation, if the result has an even number of 1’s, the flag is set. If it has an odd number of 1’s, the flag is reset. Carry flag (CY) : If an arithmetic operation results in a carry, the carry flag is set. Otherwise it is reset DEPARTMENT OF ELECTRICAL AND ELECTRONICS ENGINEERING,MVIT ,PUDUCHERRY UNIT-1 MICROPROCESSOR ARCHITECTURE J.VIJAYA RAGHAVAN -AP/EEE , MVIT,Puducherry. 27. What is the function of accumulator? SEPT 2020. The accumulator is the register associated with the ALU operations and sometimes I/O operations. It is an integral part of ALU. It holds one of data to be processed by ALU. It also temporarily stores the result of the operation performed by the ALU. 28. What is stack? NOV 2015, APRIL 2016. The stack is a group of memory locations in the R/W memory that is used for the temporary storage of binary information during the execution of the program. The stack related instructions are PUSH & POP 29. What is the program counter of 16 bit registers? SEPT 2020. This register is a memory pointer. The microprocessor uses this register to sequence the execution of the instructions. The function of the program counter is to point to the memory address from which the next byte is to be fetched. When a byte is being fetched, the program counter is automatically incremented by one to point to the next memory location 30. Define stack pointer. SEPT 2020,NOV 2017 Stack pointer is a special purpose 16-bit register in the Microprocessor, which holds the address of the top of the stack. 31. List the operations performed by the timing and control section of a microprocessor. MAY 2018. It provides timing and control signal to the microprocessor to perform the various operation. It has three control signal. It controls all external and internal circuits. It operates with reference to clock signal.It synchronizes all the data transfers. 32. Write the significance of timing and control section of microprocessors. APRIL 2013. Timing and Controlling unit in 8085 for the generation of timing signals and the signals to control.All the operations and functions both interior and exterior of a microprocessor are controlled by this unit. Every operation in the entire 8085 system occurs with the given synchronization process with the clock. DEPARTMENT OF ELECTRICAL AND ELECTRONICS ENGINEERING,MVIT ,PUDUCHERRY UNIT-1 MICROPROCESSOR ARCHITECTURE J.VIJAYA RAGHAVAN -AP/EEE , MVIT,Puducherry. 33. What is PSW of 8085? NOV 2017 Program Status(flags) Word (16 bits) abbreviated as PSW called mnemonic is a 16 bit word, a combination of contents of 8 bit flag register and the contents of 8 bit Accumulator register. 34. State the function of HOLD pin in 8085. APRIL 2015 HOLD indicates that a peripheral such as DMA controller is requesting the use of address bus, data bus and control bus. 35. What is the significance of HOLD signal available8085 Microprocessor? NOV 2015 HOLD indicates that a peripheral such as DMA controller is requesting the use of address bus, data bus and control bus. 36. List the 16 – bit registers of 8085 microprocessor? Stack pointer (SP) and Program counter (PC). B - Register C - Register D - Register E - Register H - Register L - Register Stack pointer (SP) - 16 Bit Program Counter (PC) - 16 Bit 37. List the allowed register pairs of 8085? B-C register pair D-E register pair H-L register pair B register C register D register E register H register L register 38. Mention the purpose of SID and SOD lines? SID (Serial input data line): It is an input line through which the microprocessor accept serialdata. DEPARTMENT OF ELECTRICAL AND ELECTRONICS ENGINEERING,MVIT ,PUDUCHERRY UNIT-1 MICROPROCESSOR ARCHITECTURE J.VIJAYA RAGHAVAN -AP/EEE , MVIT,Puducherry. SOD (Serial output data line): It is an output line through which the microprocessor sends output serial data. 39. What is an Opcode? The part of the instruction that specifies the operation to be performed is called the operation code or opcode. For example, in "MOV R, #0C", MOV is the opcode ("move this value into this register"), while R (register ) and #0C (the number 12) are operands. 40. What is the function of IO/M signal in the 8085? It is a status signal. It is used to differentiate between memory locations and I/O operations. When this signal is low (IO/M = 0) it denotes the memory related operations. When this signal is high (IO/M = 1) it denotes an I/O operation. 41. State the use of RESET IN and RESET OUT pins of 8085 processor. NOV/DEC 2016. RESET IN − This signal is used to reset the microprocessor by setting the program counter to zero. RESET OUT − This signal is used to reset all the connected(PERIPHERAL) devices when the microprocessor is reset. 42. In what way interrupts are classified in 8085? In 8085 the interrupts are classified as Hardware and Software interrupts. 43. What are Hardware interrupts? 5 types TRAP, RST7.5, RST6.5, RST5.5, INTR. 44. What are Software interrupts? 7 types RST0, RST1, RST2, RST3, RST4, RST5, RST6, RST7. 45. Which interrupt has the highest priority? TRAP has the highest priority. 46. How many interrupts are there in 8085? There are 12 interrupts in 8085. 47. What are the interrupts available in 8085? NOV 2019 The 8085 has 5 interrupt signals; they are INTR, RST7.5, RST6.5, RST5.5 and TRAP DEPARTMENT OF ELECTRICAL AND ELECTRONICS ENGINEERING,MVIT ,PUDUCHERRY UNIT-1 MICROPROCESSOR ARCHITECTURE J.VIJAYA RAGHAVAN -AP/EEE , MVIT,Puducherry. 48. What is the need for timing diagram? (December 2014) The timing diagram provides information regarding the status of various signals, when a machine cycle is executed. The knowledge of timing diagram is essential for system designer to select matched peripheral devices like memories, latches, ports, etc., to form a microprocessor system. 49.Define instruction cycle, machine cycle. MAY 2018, NOV 2017, NOV 2013, APRIL/MAY 2012, APRIL/MAY 2016 The sequence of operations that a processor has to carry out while executing the instruction is called Instruction cycle. Each instruction cycle of a processor indium consists of a number of machine cycles. Machine cycle is defined as the time required to complete one operation of accessing memory, I/O, or acknowledging an external request. This cycle may consist of three to six T- states. 50. Define T-State. (November 2015 & April 2015) T-State is defined as one subdivision of the operation performed in one clock period. These subdivisions are internal states synchronized with the system clock, and each T-State is precisely equal to one clock period. T state=operation performed in 1 Clkperiod. 51. How many machine cycle are needed to execute STA 1800? NOV 2017 Instruction STA 1800h requires 3-Bytes, 4-Machine Cycles (Opcode Fetch, Memory Read, Memory Read, Memory Write) And 13 T-States For Execution 52. Calculate the Time required to execute MVI instruction? (May 2014) Consider an example for MVI instructions as: Timing diagram for MVI B, 43H Fetching the Opcode 06H from the memory 2000H. (OF machine cycle) 4T states Read (move) the data 43H from memory 2001H. (memory read) 3T states In total 4T + 3T = 7T States. DEPARTMENT OF ELECTRICAL AND ELECTRONICS ENGINEERING,MVIT ,PUDUCHERRY UNIT-1 MICROPROCESSOR ARCHITECTURE J.VIJAYA RAGHAVAN -AP/EEE , MVIT,Puducherry. 53.How wait states are introduced in 8085 microprocessor during execution of a program? NOV 2017, APRIL 2015 This state is used by slow peripheral devices. The peripheral devices can transfer the data to or from the microprocessor by using READY input line. The microprocessor remains in wait state as long as READY line is low. During the wait state, the contents of the address, address/data and control buses are held constant 54. What is the need for interfacing? APRIL/ MAY 2017 The primary function of memory interfacing is that the microprocessor should be able to read from and write into a given register of a memory chip. To perform these operations the microprocessor should Be able to select the chip Identify the register Enable the appropriate buffer 55. Mention the address and data bus size of Z80 and MC6800 microprocessor. APRIL 2016. In Motorola MC6800 the data size is 8-bit and address size is 16 bit. In ZiglogZ80 the data size is 8-bit and address size is 16 bit. 56. Compare the microprocessors Z80 and 8085 in-terms of multiplexing of data lines and operating frequency. MAY 2018. 8085 Z80 Low order address and data lines are Separate lines are provided for address multiplexed and data Maximum internal clock frequency is Maximum internal clock frequency is 3 Mhz 2.5 Mhz 57. Write the memory capacity of Z80 and MC6800microprocessors. MAY 2019 Z80 uses 16-bit address for memory and so it candirectly access 64k(216 =64k)memory locations. M6800 uses 16-bit address to access memory locations and so it can directly address 64k(216 =64k)memory locations DEPARTMENT OF ELECTRICAL AND ELECTRONICS ENGINEERING,MVIT ,PUDUCHERRY UNIT-1 MICROPROCESSOR ARCHITECTURE J.VIJAYA RAGHAVAN -AP/EEE , MVIT,Puducherry. 58. What are the additional features in Z80, when compared to 8085? The Z80 has separate pins for data and address. The Z80 provides more register ,extra addressing modes, a larger instruction set than 8085 and it has built-in-logic to refresh dynamic RAM memories. The Z80 has indexed addressing mode. 59. What are shadow register of Z80? Each register of Z80 has an alternate register. The set of alternate registers are called shadow registers. 60. What are the common features of 8085 and Z80? The common features of 8085 and Z80 are the following: Fabricated using NMOS technology and has 40-pins. Memory is accessed by 16-bit address and I/O device by 8-bit address. The 8085 is software compatible with Z80. 61. List the difference between 8085 and Z80. 8085 Z80 Low order address and data lines are Separate lines are provided for address multiplexed. and data A single signal is IO/^M used to Separate signals are used to differentiate I/O. differentiate memory address and I/O address. The instruction size is one to three The instruction size is one to four bytes. bytes. The flag register has five flags The flag register has six flags. It has five hardware interrupts. It has two hardware interrupts. It has 74 types of instruction. It has 156 types of instruction. 62. What is the data and address size in Motorola 6800? In Motorola 6800 the data size is 8-bit and address size is 16-bit. 63. What are the flags of M6800? The M6800 has six flags. They are 1. Negative (N) 2. Zero (Z) 3. Overflow (V) 4. Carry(C) DEPARTMENT OF ELECTRICAL AND ELECTRONICS ENGINEERING,MVIT ,PUDUCHERRY UNIT-1 MICROPROCESSOR ARCHITECTURE J.VIJAYA RAGHAVAN -AP/EEE , MVIT,Puducherry. 5. Half carry (H) 6. Interrupt enable/disable (I). 64. What are the addressing modes available in Motorola 6800? The addressing modes of motorola6800 are immediate, direct, indexed and relative addressing. 65.List the difference between 8085 and M6800. 8085 M6800 Low order address and data lines are Separate lines are provided for address multiplexed. and data. It has 16-bit address for memory and 8- It does not have separate address for bit address. memory and I/O mapped devices. The flag register has five flags. The flag register has six flags. It has five hardware interrupts. It has two hardware interrupts. 66.what is wait state? The T-state introduced between T2 and T3 of a machine cycle by the slow peripherals (to get extra time for read/write operation)are called wait states. 67. What happens when HLT instruction is executed in processor? The Micro Processor enters into Halt-State and the buses are tri-stated. 68. What is Tri-state logic? Three Logic Levels are used and they are High, Low, High impedance state. The high and low are normal logic levels & high impedance state is electrical open circuit conditions. Tri- state logic has a third line called enable line. 69. Give an example of one address microprocessor? 8085 is a one address microprocessor. DEPARTMENT OF ELECTRICAL AND ELECTRONICS ENGINEERING,MVIT ,PUDUCHERRY UNIT-1 MICROPROCESSOR ARCHITECTURE J.VIJAYA RAGHAVAN -AP/EEE , MVIT,Puducherry. UNIVERSITY QUESTIONS 1. What is microprocessor? NOV 2013, APRIL/ MAY 2017 2. What is software and hardware? NOV 2013 3. Name the types of buses in microprocessor. NOV 2017 3. Why is address bus unidirectional? APRIL/MAY 2017 4. Why data bus is bi-directional? NOV/DEC 2016 5. What is the need of ALE signals m 8085processor? NOV/DEC 2016 6. How are the address and data lines demultiplexed in 8085? APRIL/MAY 2017, NOV/DEC 2016, NOV/DEC 2018 7. Specify the size of data, address, and memory word and memory capacity of 8085 microprocessor. NOV/DEC 2016. 8. Write the significance of control section in microprocessors. MAY 2019 9. List four operations commonly performed by the Microprocessor? NOV 2015 10. Write the significance of Arithmetic and Logic section of a microprocessor. APRIL/MAY 2016. 11. What is the significance of general purpose registers in 8085? APRIL/MAY 2012 12. Give the flag register format/bit pattern of 8085. MAY 2018, APRIL 2013. 13. List and define the function of flags in 8085. APRIL/MAY 2017, APRIL/MAY 2012, NOV 2019, NOV/DEC 2018, NOV/DEC 2016. 14. What is the function of accumulator? SEPT 2020. 15. What is stack? NOV 2015, APRIL 2016. 16. What is the program counter and the stack pointer of 16 bit registers? SEPT 2020. 17. Define stack pointer. SEPT 2020.NOV 2 017 18. List the operations performed by the timing and control section of a microprocessor. MAY 2018. 19. Write the significance of timing and control section of microprocessors. APRIL 2013. 20. What is PSW of 8085? NOV 2017 21. State the function of HOLD pin in 8085. APRIL 2015 22. State the use of RESET IN and RESET OUT pins of 8085 processor. NOV/DEC 2016. 23. What are the interrupts available in 8085? NOV 2019 DEPARTMENT OF ELECTRICAL AND ELECTRONICS ENGINEERING,MVIT ,PUDUCHERRY UNIT-1 MICROPROCESSOR ARCHITECTURE J.VIJAYA RAGHAVAN -AP/EEE , MVIT,Puducherry. 24. Define instruction cycle, machine. cycle and T-state. MAY 2018, NOV 2017, NOV 2013, APRIL/MAY 2012, APRIL/MAY 2016 25. How many machine cycle are needed to execute STA 1800? NOV 2017 26.How wait states are introduced in 8085 microprocessor during execution of a program ? NOV 2017, APRIL 2015 27. What is the need for interfacing? APRIL/ MAY 2017 28. Mention the address and data bus size of Z80 and.MC6800 microprocessor. APRIL 2016. 29. Compare the microprocessors Z80 and 8085 in-terms of multiplexing of data lines and operating frequency. MAY 2018. 30. Write the memory capacity of Z80 and MC6800microprocessors. MAY 2019 31. What is the significance of HOLD signal available8085 Microprocessor? NOV 2015 DEPARTMENT OF ELECTRICAL AND ELECTRONICS ENGINEERING,MVIT ,PUDUCHERRY