Laptop User Manual

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.
BL somewhere ; This nested call will overwrite R14
LDMED SP!,{R0-R3,R15} ; Restore workspace and return.