User manual

APC-3X97A user manual
54
outportb(0x4F, (inportb(0x4F)|0x2));
//Set bit[1] to enable GPIO Port2 if LDN=9
Or
outportb(0x4E, 0x30); //Logic device activation control
outportb(0x4F, (inportb(0x4F)|0x4));
//Set bit[2] to enable GPIO Port6 if LDN=8
 Configure GPIO register
Example x86 assembly code:
mov dx, 4Eh
mov al, 0E6h ;GPIO inversion reg.
out dx, al
mov dx, 4Fh
mov al, 000h ;0 – normal, 1 - inverted
out dx, al
mov dx, 4Eh
mov al, 0E4h ;GPIO I/O selection reg.
out dx, al
mov dx, 4Fh
mov al, 0FFh ;0 – Output, 1 – Input
;or mov al, 0F0h to set output
out dx, al
Example C code:
outportb(0x4E, 0xE6); //GPIO I/O selection reg.
outportb(0x4F, 0x0); //0 – normal, 1 - inverted
outportb(0x4E, 0xE4); //GPIO inversion reg.
outportb(0x4F, 0xFF); //0 – Output, 1 - Input
or
outportb(0x4E, 0xE4); //GPIO inversion reg.
outportb(0x4F, 0xF0); //0 – Output, 1 - Input
 Read GPIO value
Example x86 assembly code:
mov dx, 4Eh
mov al, 0E5h ;GPIO data reg.
out dx, al
mov dx, 4Fh
in al, dx ;Bit[3::0] = GPI[3::0] value