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authorJuan J. Martinez <jjm@usebox.net>2020-12-30 19:07:31 +0000
committerJuan J. Martinez <jjm@usebox.net>2020-12-30 19:23:41 +0000
commit2682bc5d1d864341aaeb42a449db73c3ecd16d70 (patch)
tree9116764364b4ee0ce7f6037305077807b57776de /src/ubox/ubox_wait.z80
downloadubox-msx-lib-2682bc5d1d864341aaeb42a449db73c3ecd16d70.tar.gz
ubox-msx-lib-2682bc5d1d864341aaeb42a449db73c3ecd16d70.zip
Initial import1.0
Diffstat (limited to 'src/ubox/ubox_wait.z80')
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1 files changed, 23 insertions, 0 deletions
diff --git a/src/ubox/ubox_wait.z80 b/src/ubox/ubox_wait.z80
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+.globl _ubox_wait
+.globl ubox_isr_wait_ticks
+.globl ubox_isr_wait_tick
+
+_ubox_wait::
+ ld hl, #ubox_isr_wait_tick
+ ld a, (ubox_isr_wait_ticks)
+ ld c, a
+
+wait_loop:
+ ld a, (hl)
+ cp c
+ jr nc, wait_done
+ halt
+ jr wait_loop
+
+wait_done:
+ xor a
+ di
+ ld (hl), a
+ ei
+ ret
+