Asus Aaeon PCM-CFS, User Manual

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Appendix C – Digital I/O Ports 111
5.2
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GPIO8 Pin Status Register – Index 8Ah (This byte could be also read by base a 2)
Bit Name R/W Reset Default Description
7 GPIO87_IN R - - The pin status of GPIO87/PD7
6 GPIO86_IN R - - The pin status of GPIO86/PD6
5 GPIO85_IN R - - The pin status of GPIO85/PD5
4 GPIO84_IN R - - The pin status of GPIO84/PD4
3 GPIO83_IN R - - The pin status of GPIO83/PD3
2 GPIO82_IN R - - The pin status of GPIO82/PD2
1 GPIO81_IN R - - The pin status of GPIO81/PD1
0 GPIO80_IN R - - The pin status of GPIO80/PD0
C.2 Digital I/O Sample Code (4 in, 4 out; 2 low, 2 high)
Outportb(0x2E,0x87); //enter configuration Outportb(0x2E,0x87);
Outportb(0x2E,0x07); //set LDN
Outportb(0x2F,0x06);
Outportb(0x2E,0x88); //GPIO set 8x Output enable register
Outportb(0x2F,0xF0);
Outportb(0x2E,0x89); //GPIO 8x output data register
Outportb(0x2F,0x30);
Outportb(0x2E,0xAA); //exit configuration