Microprocessor Technology Quiz Questions

Moon is round because of formed and collapsed under the force of their own gravity.

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.

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.

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.

During the night the high contrast between the bright moon and the night's dark skies make the Moon look white.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

The POP PSW instruction in a microprocessor will take 3 machine cycles and 10 T states to complete.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.