It may be useful to force the CPU to wait a little for external (maybe slower) devices to complete their work and report data to the CPU, i.e. NOP is useful for synchronization purposes.
Q. What is the use of NOP instructions?
A NOP is most commonly used for timing purposes, to force memory alignment, to prevent hazards, to occupy a branch delay slot, to render void an existing instruction such as a jump, or as a place-holder to be replaced by active instructions later on in program development (or to replace removed instructions when …
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Q. What is the use of NOP instruction in pipelining?
A NOP is an instruction that does nothing (has no side-effect). MIPS assembler often support a nop instruction but in MIPS this is equivalent to sll $zero $zero 0 . This instruction will take up all 5 stages of pipeline.
Q. What is LDR and STR?
Generally, LDR is used to load something from memory into a register, and STR is used to store something from a register to a memory address. Then we load the value stored at the memory address found in R0 to R2, and store the value found in R2 to the memory address found in R1.
Q. How does MOV work in assembly?
The mov instruction copies the data item referred to by its second operand (i.e. register contents, memory contents, or a constant value) into the location referred to by its first operand (i.e. a register or memory). While register-to-register moves are possible, direct memory-to-memory moves are not.
Q. What is LDR in assembly language?
The LDR Rd,= label pseudo-instruction places an address in a literal pool and then loads the address into a register. The assembler converts an LDR Rd,= label pseudo-instruction by: Placing the address of label in a literal pool (a portion of memory embedded in the code to hold constant values).
Q. What is the difference between ADR and LDR?
LDR obtains the immediate data by putting the data in the program code and uses a PC relative load to get the data into the register. ADR tries to generate the immediate value by adding or subtracting instructions (for example, based on the current PC value).
Q. How does an LDR work?
The working principle of an LDR is photoconductivity, which is nothing but an optical phenomenon. When the light is absorbed by the material then the conductivity of the material enhances. When the light falls on the LDR, then the electrons in the valence band of the material are eager to the conduction band.
