What does MOV PC LR do?

What does MOV PC LR do?

simple Function Call BL (branch and link) and MOV PC, LR are the two essential instructions needed for a function call and return. BL performs two tasks: it stores the return address of the next instruction (the instruction after BL) in the link register (LR), and it branches to the target instruction.

What is PC and LR?

LR is the link register a shortcut for r14. And PC is the program counter a shortcut for typing r15. When you perform a call, called a branch link instruction, bl, the return address is placed in r14, the link register. the program counter pc is changed to the address you are branching to.

What is BX LR?

Written by “bl” (branch and link, like function call), often saved with a push/pop sequence, read by “bx lr” (branch to link register) or the pop.

What does MOV mean in arm?

Usage. The MOV instruction copies the value of Operand2 into Rd . The MVN instruction takes the value of Operand2 , performs a bitwise logical NOT operation on the value, and places the result into Rd . In certain circumstances, the assembler can substitute MVN for MOV , or MOV for MVN .

What is BX in arm?

bx stands for branch and exchange instruction set Which means that according to the lsb (least significant bit) of the address to branch to, the processor will treat the next instruction as ARM or as thumb.

What type of instruction is MOV?

In 8085 Instruction set, MOV is a mnemonic, which stands for “MOVe”.

Which register is LR?

link register
On an ARM Cortex M series device, the link register (LR or R14) is a core register that stores the return address, such as when making a function call. In the case of an exception, the return address is pushed onto the stack by hardware and the LR is set to EXC_RETURN (0xFFFFFFF1, 0xFFFFFFF9, or 0xFFFFFFFD).

What is BNE ARM?

BNE (short for “Branch if Not Equal”) is the mnemonic for a machine language instruction which branches, or “jumps”, to the address specified if, and only if the zero flag is clear.

What does BX do in assembly?

What is R13 in ARM?

Register R13 is used as the Stack Pointer (SP). R13 is banked for the exception modes. This means that an exception handler can use a different stack to the one in use when the exception occurred.