Sharp MZ-5600 - Page 31

ii) Software
The followingprogramming is required in order to perform interrupt
processing using the machine language.
Main routine
Interrupt routine
°Set to the top address of the
interrupt processing routine
°Clear the 8259A maske
O(Execute the STI
acknowledge
°lnterrupt processing .
command)
1
0lssue the EOl command to the 8259A
°For the MZ-5500/5600 , the following modes are assigned to the 8259A PICo
-Level trigger mode
-8086 mode
-Normal EOI mode
-Free nested mode
lnterrupt routine programming mode
(1) Jnterrupt address designation
The top address of the interrupt processing
0: IOOn
routine must be assigned at the start of
the main routine.
As shown in the figure right, the top
address of each interrupt routine can be
set in sequence from "segment 0:
offset: 100H". The top address of the
interrupt routine for the IR-26 must be
0: IOOH+4*14
written in 14th address.
Segment 0:
Offsel 100H+4*14
Offset
Segment
Offset
Segment
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