Pch 7991 – Acnodes PCH 7991 User Manual
Page 61
PCH 7991
19 inch Atom Fanless Panel PC
© Copyright 2012 Acnodes, Inc.
All rights reserved. Product description and product specifications
are subject to change without notice. For latest product information,
please visit Acnodes’ web site at www.acnodes.com.
14628 Central Ave.
Chino, CA91710
Tel:909.597.7588, Fax:909.597.1939
Exam p le x86 assem bly code:
m ov
dx, 4E h
m ov
al, 87h
out
dx, al
out
dx, al
Exam p le C code:
outportb(0x4E, 0x87);
outportb(0x4E, 0x87);
Exit the extended function mode
W riting A A h to index address port wi ll exit the ext ended function m od
Exam p le x86 assem bly code:
m ov
dx, 4E h m ov
al,
0A Ah out dx, al
Exam p le C code:
outportb(0x4E, 0xA A );
Selec t logic device number
Exam p le x86 assem bly code:
m ov
dx, 4E h
m ov
al, 0 07 h
;LDN s election regist er
out
dx, al
m ov
dx, 4Fh
m ov
al, 0 08h
;Sel ect LDN =8, GP IO Po rt6
out
dx, al
;or S elect LD N9, GP IO Port2
Exam p le C code:
outportb(0x4E, 0x07);
//LDN
s election
register
outport b(0x4F, 0x08); // Selec t LDN= 8, GP IO Port6 or
outportb(0x4E, 0x07);
//LDN selecti on regis ter
outportb(0x4 F, 0x09); //Sel ect LDN= 9, GP IO P ort2