Samsung S3C2440A User Manual

Page 103

ARM INSTRUCTION SET

S3C2440A RISC MICROPROCESSOR

3-46

EXAMPLES

LDMFD

SP!,{R0,R1,R2}

; Unstack 3 registers.

STMIA

R0,{R0-R15}

; Save all registers.

LDMFD

SP!,{R15}

;

R15

←

(SP), CPSR unchanged.

LDMFD

SP!,{R15}^

;

R15

←

(SP), CPSR <- SPSR_mode

; (allowed only in privileged modes).

STMFD

R13,{R0-R14}^

; Save user mode regs on stack

; (allowed only in privileged modes).

These instructions may be used to save state on subroutine entry, and restore it efficiently on return to the calling
routine:

STMED

SP!,{R0-R3,R14}

; Save R0 to R3 to use as workspace

; and R14 for returning.

somewhere

; This nested call will overwrite R14

LDMED

SP!,{R0-R3,R15}

; Restore workspace and return.