mirror of
https://github.com/bobbimanners/emailler.git
synced 2024-07-27 12:29:21 +00:00
39 lines
699 B
ArmAsm
39 lines
699 B
ArmAsm
;originally from Per Olofsson's IP65 library - http://www.paradroid.net/ip65
|
|
|
|
; timer routines
|
|
;
|
|
; the timer should be a 16-bit counter that's incremented by about
|
|
; 1000 units per second. it doesn't have to be particularly accurate,
|
|
; if you're working with e.g. a 60 Hz VBLANK IRQ, adding 17 to the
|
|
; counter every frame would be just fine.
|
|
|
|
|
|
.include "../inc/common.i"
|
|
|
|
|
|
.export timer_timeout
|
|
.import timer_read
|
|
|
|
.bss
|
|
|
|
time: .res 2
|
|
|
|
|
|
.code
|
|
|
|
; check if value in A/X is smaller than current timer value
|
|
timer_timeout:
|
|
pha
|
|
txa
|
|
pha
|
|
jsr timer_read
|
|
stax time
|
|
pla
|
|
tax
|
|
pla
|
|
sec ; subtract current value
|
|
sbc time
|
|
txa
|
|
sbc time + 1
|
|
rts ; clc = timeout, sec = no timeout
|