User manual

APC-3x82/83 User Manual
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3.10.4 Read/write GPIO sequence
1. Enter the extended function mode
2. Select logic device number
3. Read/write GPIO register value
4. Exit the extended function mode
3.10.5 Software programming example
Enter the extended function mode
Writing 87h to index address port twice will enter the extended function mode.
Example x86 assembly code:
mov dx, 4Eh
mov al, 87h
out dx, al
out dx, al
Example C code:
outportb(0x4E, 0x87);
outportb(0x4E, 0x87);
Exit the extended function mode
Writing AAh to index address port will exit the extended function mode.
Example x86 assembly code:
mov dx, 4Eh
mov al, 0AAh
out dx, al
Example C code:
outportb(0x4E, 0xAA);
Select logic device number
Example x86 assembly code:
mov dx, 4Eh
mov al, 007h ;LDN selection register
out dx, al
mov dx, 4Fh
mov al, 008h ;Select LDN=8, GPIO Port6
;or Select LDN9, GPIO Port2
out dx, al
Example C code:
outportb(0x4E, 0x07); //LDN selection register