1.
Which year is microprocessor first developed?
Correct Answer
B. 1971
Explanation
Moon is round because of formed and collapsed under the force of their own gravity.
2.
What is the technology used in micro-processor?
Correct Answer
A. NMOS
Explanation
NMOS (N-channel Metal-Oxide-Semiconductor) is a type of technology used in microprocessors. It refers to the use of n-channel MOSFETs (Metal-Oxide-Semiconductor Field-Effect Transistors) in the construction of the microprocessor. NMOS technology was popular in early microprocessors but has largely been replaced by CMOS (Complementary Metal-Oxide-Semiconductor) technology due to its lower power consumption and higher performance. Therefore, the correct answer is NMOS.
3.
Addresable memory size of 8085?
Correct Answer
B. 64KB
Explanation
The addressable memory size of the 8085 microprocessor is 64KB. This means that the microprocessor can access and manipulate data stored in a memory space of up to 64 kilobytes.
4.
What is the use of ALE signal?
Correct Answer
B. Latching & multiplexing
Explanation
During the night the high contrast between the bright moon and the night's dark skies make the Moon look white.
5.
What S0=1 and S1=1 indicate?
Correct Answer
A. Fetch
Explanation
S0=1 and S1=1 indicate the fetch operation. In a computer's control unit, S0 and S1 are control signals that determine the sequence of operations. When S0=1 and S1=1, it means that the control unit is in the fetch state, where it is retrieving the next instruction from memory. This is the initial step in the instruction cycle, where the control unit fetches the instruction to be executed from memory.
6.
What S0=0 and S1=1 indicate?
Correct Answer
C. Write
Explanation
S0=0 and S1=1 indicate the write operation. In computer systems, S0 and S1 are control signals that determine the operation to be performed. In this case, when S0 is 0 and S1 is 1, it signifies that the system is performing a write operation, which involves writing data into a memory location or a register.
7.
How many bits are unused in PSW?
Correct Answer
B. 3
Explanation
The answer is 3 because the Program Status Word (PSW) is a 16-bit register in a computer system. Out of these 16 bits, only 13 bits are used for specific purposes, such as storing flags, control bits, and other relevant information. The remaining 3 bits are unused and do not have any assigned function or meaning in the PSW.
8.
How many 16 bit registers are used by 8085?
Correct Answer
A. 3
Explanation
The 8085 microprocessor uses three 16-bit registers. These registers are the program counter (PC), the stack pointer (SP), and the instruction register (IR). The program counter keeps track of the memory address of the next instruction to be executed. The stack pointer is used to manage the stack, which is a region of memory used for temporary storage. The instruction register holds the current instruction being executed.
9.
How many software interrupts are there in 8085?
Correct Answer
B. 8
Explanation
The correct answer is 8 because the 8085 microprocessor has 8 software interrupts, which are interrupt instructions that can be used by the programmer to interrupt the normal program flow and execute a specific subroutine. These software interrupts are identified by the numbers 0 to 7 and can be invoked by using the RST (Restart) instruction followed by the corresponding interrupt number.
10.
Which is the interrupt dealing with peripherals?
Correct Answer
A. INTR
Explanation
INTR is the interrupt dealing with peripherals. It is a hardware interrupt that is triggered by external devices to request attention from the CPU. When an external device needs to communicate with the CPU, it sends an interrupt signal to the CPU through the INTR pin. The CPU then suspends its current task, saves its state, and jumps to the interrupt service routine to handle the request from the peripheral device. INTR is specifically designed for handling peripheral-related interrupts, making it the correct answer for this question.
11.
Which is the NMI in 8085?
Correct Answer
A. TRAP
Explanation
The NMI (Non-Maskable Interrupt) in the 8085 microprocessor is represented by the TRAP instruction. The TRAP instruction is used to handle critical errors or emergencies that cannot be masked or ignored. When a TRAP instruction is encountered, the microprocessor jumps to a fixed memory location to execute a specific routine. This allows the system to handle urgent tasks or events that require immediate attention, ensuring the stability and reliability of the system.
12.
Which harware interrupt is not vectored?
Correct Answer
B. INTR
Explanation
The hardware interrupt that is not vectored is INTR. Vectored interrupts are those that have a specific address associated with them, allowing the processor to directly jump to the appropriate interrupt service routine. However, INTR is a non-vectored interrupt, meaning that it does not have a specific address associated with it. Instead, it relies on the interrupt service routine to manually determine the cause of the interrupt and handle it accordingly.
13.
How many pins in 8085 function as input , output both?
Correct Answer
B. 8
Explanation
In the 8085 microprocessor, 8 pins are capable of functioning as both input and output. These pins can be programmed to either receive data from external devices or send data to them. This versatility allows for efficient communication between the microprocessor and other components of a system.
14.
What are the three categories of Microprocessor?
Correct Answer
A. Genreal Purpose, Special Purpose , Embedded System
Explanation
The correct answer is General Purpose, Special Purpose, and Embedded System. These are the three categories of microprocessors. General Purpose microprocessors are designed for a wide range of applications and can perform various tasks. Special Purpose microprocessors are designed for specific tasks or functions, such as graphics processing or signal processing. Embedded System microprocessors are designed to be integrated into a larger system or device, such as a car or a smartphone, and perform specific functions within that system.
15.
8085 follows which architecture?
Correct Answer
A. Von Neuman
Explanation
The 8085 follows the Von Neumann architecture. This architecture is characterized by having a single memory space for both data and instructions, and a single bus for transferring data and instructions between the memory and the processor. In this architecture, the program instructions and data are stored in the same memory, and the processor fetches and executes instructions one at a time. This architecture is widely used in most modern computers and microprocessors.
16.
Operating frequency of 8085 is
Correct Answer
A. 3 Mhz
Explanation
The operating frequency of the 8085 microprocessor is 3 MHz. This means that the microprocessor can perform 3 million cycles per second. The frequency determines the speed at which the microprocessor can execute instructions and process data. A higher frequency allows for faster processing, while a lower frequency may result in slower performance. Therefore, the correct answer is 3 MHz as it accurately represents the operating frequency of the 8085 microprocessor.
17.
How many pins are used for clock
Correct Answer
A. 3
Explanation
The correct answer is 3 because in a clock, there are typically three pins used to indicate the hour, minute, and second hands. Each pin corresponds to a specific unit of time, allowing the clock to accurately display the current time.
18.
How many T States Fetch cycle needs?
Correct Answer
A. 4
Explanation
The Fetch cycle in a computer processor is responsible for fetching the next instruction from memory. It consists of four T states, which represent the different stages of the cycle. These T states include the memory read operation, instruction decoding, and the preparation for the execution of the instruction. Therefore, the correct answer is 4.
19.
An MVI Instruction will need how many T States?
Correct Answer
A. 7
Explanation
An MVI instruction, which stands for "Move Immediate," is used to move a constant value into a register in a microprocessor. This instruction typically takes 7 T states to complete. T states refer to the number of clock cycles required to execute an instruction. Therefore, the correct answer is 7.
20.
An Instruction will need minimum how many T States?
Correct Answer
A. 4
Explanation
The instruction will need a minimum of 4 T states. T states, or clock cycles, are the time intervals required for the execution of each instruction. In this case, the instruction will need at least 4 T states to complete its execution.
21.
Which is register used for communication with peripheral device?
Correct Answer
B. A
Explanation
The correct answer is A because registers are used to store data temporarily during communication with peripheral devices. They act as a buffer between the processor and the peripheral device, allowing for efficient data transfer and synchronization.
22.
How is the power supply of 8085 different from 8080?
Correct Answer
A. 8080 - 12V , 8085 - 5V
Explanation
The power supply of the 8085 is different from the 8080 because the 8080 requires a power supply of 12V, while the 8085 requires a power supply of 5V.
23.
How many I/O ports can 8085 access?
Correct Answer
C. 256
Explanation
The 8085 microprocessor can access a total of 256 I/O ports. This means that it can communicate with and control up to 256 different input and output devices, such as keyboards, displays, printers, and sensors. These I/O ports provide the necessary interface for the microprocessor to interact with the external world and exchange data and signals.
24.
No.of general purpose 8 bit registers in 8085?
Correct Answer
B. 8
Explanation
The 8085 microprocessor has a total of 8 general-purpose 8-bit registers. These registers are used for various operations and data manipulation within the microprocessor. They can store 8 bits of data and can be used for arithmetic, logical, and data transfer operations. Having 8 registers provides flexibility and efficiency in processing data within the microprocessor.
25.
No. of temporary registers in 8085?
Correct Answer
D. 3
Explanation
The 8085 microprocessor has a total of 7 registers, out of which 3 are general-purpose registers (B, C, and D) that can be used as temporary registers. These registers are used to store intermediate values during calculations or data manipulation. Therefore, the correct answer is 3.
26.
When is parity flag set?
Correct Answer
B. Result contains even no. of 1's
Explanation
The parity flag is set when the result contains an even number of 1's. This means that if the binary representation of the result has an even number of 1's, the parity flag will be set. If there are an odd number of 1's, the parity flag will not be set. The parity flag is used in computer systems to check for errors in data transmission or storage.
27.
When is sign flag set?
Correct Answer
A. If the MSB of the result of an operation is 1
Explanation
The sign flag is set when the Most Significant Bit (MSB) of the result of an operation is 1. The MSB represents the sign of a number in binary representation, where 0 indicates a positive number and 1 indicates a negative number. Therefore, when the MSB is 1, it means that the result of the operation is a negative number, and the sign flag is set to indicate this.
28.
Minimum time required for the effective RESET IN signal?
Correct Answer
C. 3 clock cycle
Explanation
The effective RESET IN signal requires a minimum of 3 clock cycles to reset. This means that it takes 3 clock cycles for the signal to be fully reset and ready for the next operation. During these 3 clock cycles, the necessary operations are performed to ensure that the signal is properly reset and any previous data or state is cleared.
29.
Types of machine cycles in 8085?
Correct Answer
A. 7
Explanation
The correct answer is 7 because the 8085 microprocessor has a total of 7 machine cycles. These machine cycles include the opcode fetch cycle, memory read cycle, memory write cycle, I/O read cycle, I/O write cycle, interrupt acknowledge cycle, and the restart cycle. Each of these cycles performs a specific task in the execution of instructions and the overall functioning of the microprocessor.
30.
How many registers of 8085 are programmable?
Correct Answer
D. 6
Explanation
The correct answer is 6 because the 8085 microprocessor has six registers that are programmable, namely B, C, D, E, H, and L. These registers can be used to store data and perform various operations during program execution. The other two registers, A (Accumulator) and the Program Counter (PC), are also important but not programmable. Therefore, out of the total eight registers in the 8085 microprocessor, six are programmable.
31.
Minimum T State consumed by a machine cycle in 8085?
Correct Answer
C. 3
Explanation
The minimum T state consumed by a machine cycle in the 8085 microprocessor is 3. This means that it takes a minimum of 3 clock cycles for the machine cycle to complete. Each T state represents a single clock cycle, and the 8085 microprocessor requires at least 3 clock cycles to execute a machine cycle.
32.
Maximum no. of T State consumed by a machine Cycle?
Correct Answer
A. 4
Explanation
The maximum number of T states consumed by a machine cycle is 4. T states are a measure of the time taken by a microprocessor to complete an instruction cycle. Each machine cycle consists of multiple T states, including fetch, decode, execute, and memory access. The answer of 4 suggests that the machine cycle in question requires a maximum of 4 T states to complete.
33.
PCHL instruction has how many machine cycles?
Correct Answer
A. 1
Explanation
The PCHL instruction has only one machine cycle. This means that it takes only one cycle of the computer's clock to complete the execution of this instruction.
34.
PCHl instruction consumes how many T-States?
Correct Answer
B. 6
Explanation
The PCHL instruction in assembly language programming consumes 6 T-States. T-States, or timing states, are a measure of the time taken by a microprocessor to execute an instruction. In this case, the PCHL instruction is used to load the Program Counter (PC) with the contents of the H and L registers. The execution of this instruction requires 6 T-States.
35.
ADD M uses which kind of addressing mode?
Correct Answer
B. Register Indirect
Explanation
ADD M uses the Register Indirect addressing mode. In this mode, the instruction operates on the value stored in the memory location pointed to by the contents of a register. In the case of ADD M, the instruction would retrieve the value from the memory location specified by the contents of the register M and perform the addition operation. This addressing mode is commonly used when working with data stored in memory rather than directly in registers.
36.
POP PSW will have how many machine cycle & T State?
Correct Answer
A. 3,10
Explanation
The POP PSW instruction in a microprocessor will take 3 machine cycles and 10 T states to complete.
37.
DAD has how many machine cycle & T State?
Correct Answer
A. 2,10
Explanation
The correct answer is 2,10. This means that DAD instruction requires 2 machine cycles and 10 T states to complete. Machine cycles refer to the number of basic operations needed to execute an instruction, while T states represent the number of clock cycles required for each machine cycle. In this case, the DAD instruction takes 2 machine cycles and each cycle requires 10 T states to finish.
38.
If IN instruction starts from 4125 H , what will be the contents of A8-A15 in the second machine cycle?
Correct Answer
B. 41H
Explanation
In the given question, it is stated that the IN instruction starts from memory address 4125H. During the second machine cycle of the IN instruction, the contents of the Accumulator are transferred to the A8-A15 lines. Therefore, the contents of A8-A15 in the second machine cycle will be the same as the contents of the Accumulator, which is 41H.