Which of the following is 2 byte instruction?
Two-byte instructions – Two-byte instruction is the type of instruction in which the first 8 bits indicates the opcode and the next 8 bits indicates the operand. In a two-byte instruction, the first byte specifies the operation code and second byte specifies the operand.
How many bytes are present in instruction of 8085 microprocessor?
Only ONE/TWO/THREE byte instructions are available in 8085 microprocessor. 8085 can support only upto 3 byte instruction formats. This is because 8085 can process maximum of two byte operand followed by a byte opcode.
What are in and out instructions?
The IN instruction is used to move data from an I/O port into the accumulator. The OUT instruction is used to move data from the accumulator to an I/O port. The IN & OUT instructions are used only on microprocessor, which use a separate address space for interfacing.
Which of the following instruction requires 2 bytes storage?
2 – Byte Instructions 1st byte specifies opcode and 2nd byte specifies operand. Instructions require two memory locations to store in the memory.
What is the size of instruction queue in 8086?
6-bytes
What is the memory size instruction queue?
Instruction queue is 6 bytes so that it can store the longest instruction. 8086 is the Ist processor to support Instruction Queue.
What is the function of instruction queue?
Instruction queue Usually the processor execution speed is much faster than the memory access speed. Instruction queue is used to prefetch the next instructions in a separate buffer while the processor is executing the current instruction.
What happens if there is no instruction byte queue in 8086?
The 8086 BIU will not initiate a fetch unless and until there are two empty bytes in its queue. 8086 BIU normally obtains two instruction bytes per fetch.
Which queue is used in 8086 processor?
Explanation: In 8086, a 6-byte instruction queue is presented at the Bus Interface Unit (BIU). It is used to prefetch and store at the maximum of 6 bytes of instruction code from the memory. Due to this, overlapping instruction fetch with instruction execution increases the processing speed.
What is the necessity of prefetch queue?
Prefetch queueing accesses memory in parallel with CPU operations trying to maintain a queue of four (8088) to six (8086) bytes beyond the current instruction being executed.
Why is 8086 memory divided into two units?
The architecture of 8086 is divided into two functional parts i.e. Functional division of architecture speeds up the processing, since BIU and EU operate parallel and independently i.e., EU executes the instructions and BIU fetches another instruction from the memory simultaneously.