mirror of
https://github.com/cc65/cc65.git
synced 2024-12-27 15:29:46 +00:00
37 lines
543 B
ArmAsm
37 lines
543 B
ArmAsm
|
;
|
||
|
|
; Ullrich von Bassewitz, 2003-04-13
|
||
|
|
;
|
||
|
|
; clock_t clock (void);
|
||
|
|
;
|
||
|
|
|
||
|
|
.export _clock
|
||
|
|
.import negax
|
||
|
|
.importzp sreg
|
||
|
|
|
||
|
|
.include "atmos.inc"
|
||
|
|
|
||
|
|
|
||
|
|
.proc _clock
|
||
|
|
|
||
|
|
; Clear the timer high 16 bits
|
||
|
|
|
||
|
|
ldy #$00
|
||
|
|
sty sreg
|
||
|
|
sty sreg+1
|
||
|
|
|
||
|
|
; Read the timer
|
||
|
|
|
||
|
|
sei ; Disable interrupts
|
||
|
|
lda TIMER3
|
||
|
|
ldx TIMER3+1
|
||
|
|
cli ; Reenable interrupts
|
||
|
|
|
||
|
|
|
||
|
|
; Since the timer is counting downwards, return the negated value
|
||
|
|
|
||
|
|
jmp negax
|
||
|
|
|
||
|
|
.endproc
|
||
|
|
|
||
|
|
|