2018_05_17 수업자료

Special Purpose General Register

-Program counter(r15 =pc)

A Pointer to the instruction

-Link Register(r14 = lr)

To hold the address of the next instruction after a Branch will

Register(2)

Status Register

-CPSR(Current Program Status Register) 현재 cpsr상태

-SPSR(Saved Program Status Register) 이진모드의 cpsr 상태

n   z   c   v                    i f t m4 m3 m2 m1 m0

31 32 29 28             8    7 65  4   3    2    1    0

N: Negative /Less Than

Z: Zero

C: Carry/Borrow/Extend

V: Overflow 

T: IRQ Disable bit

F: FIQ Disable bit

T: 0 indicates ARM excution(Default)

  /1 indicate Thumb excution

M[4:0]: Present current processor mode

M[4:0]        mode

10000        User

10001        FIQ

10010        IRQ

10011        Supervisor

10111        Abort

11011        Underfinde Instruction

레지스터 : 메모리 최소 단위

레지스터 보다 큰건 캐쉬

플리플롭 : 0, 1 을 저장하는 최소 단위