Appendix E Digital I/O Interface
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Appendix E Digital I/O Interface
E.1 Introduction
The DIO connector on the AESQ170-969 is interfaced to GPIO ports on the
Super I/O chipset. The digital inputs and digital outputs are generally control
signals that control the on/off circuit of external devices or TTL devices. Data
can be read or written to the selected address to enable the DIO functions.
NOTE:
For further information, please refer to the datasheet for the Super
I/O chipset.
The BIOS interrupt call
INT 15H
controls the digital I/O.
INT 15H:
AH – 6FH
Sub-function:
AL – 8
:Set the digital port as INPUT
AL
:Digital I/O input value
E.2 Assembly Language Sample 1
MOV
AX, 6F08H
;setting the digital port as input
INT
15H
;
AL low byte = value
AH – 6FH
Sub-function:
AL – 9
:Set the digital port as OUTPUT
BL
:Digital I/O input value
E.3 Assembly Language Sample 2
MOV
AX, 6F09H
;setting the digital port as output
