Sharp MZ-5500 - Page 34

ii) Software
The following procedure is required when interrupt is processed using the
machine language.
IY\terrupt proce~)iVLj rOi.ltiV1~
~1o.lt'\ loutj' ne..
0\ ~& ~
~-Q.'h , i\~'\~~ 'Io.. , \'(\1J.-
~~ ()\~ ' ~ '{ ~i V. '
'Wa.il ~r-j\,« 1vp .Jress 0+ -the old /J
. ih\~
inre\Tupt proc.ess;n~ rou1ine
~~
Se ·t to fu -top acldre5s ~tM inierrupt . ' .
prou~'h ; t\l.~ routi0e.. ' . / . . .J"tertUpt!juJ1<1li1e.rt
(.leoy 1ttl ~sLl A Vntl'7~ I k I .
, • . "terrur~ 0.( ' How €'c{je..
• Issu~ tb fO[ comMllluJ
~l\1qA
IRE T
. ~ the
·)et -to t\~ : top OdJ;Q5S of -tt~ ,
olJ
1~1errupt pnx:es5;~ nxrltne
~ - - - - - - - - _I
. t
For theMZ-5500/5600, the following müdes are assjgned to the 8259A PICo
Für more details, refer to the 8259A specifieation sheet.
°L evel trigger mode
0: 100H
r------,
08086 mode
Offset
}IR -O
°Normal EOI
Segment
~ Free nested mode
JIR-I
~
0:100H+4*13
~
Interrupt routine ' programming mode
(1) Interrupt addre~s designation
The top address of the interrupt processing routine must be assigned at
the . start of the main routine. As shown in the fjgure right, the top
address of eaeh interrupt routine ean be set in sequence from "segment 0:
offset: 100H". The top address of the interrupt routine for the IR-25
must be
written in 13th address.
Segment 0:
Offset 100H+4*13
Before writing the address, be sure to save the address previously
writt~n.
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