Fairbanks FB3000 Kernel Program Operators Manual - Manual (Page 45)

04/12 45 51146 Rev. 3
Appendix I: GPIO Port
Programming the GPIO Port
The FB3000 embedded PCB provides an 8-bit GPI port and an 8-bit GPO port
through which to read and write data. The GPIO port base address is 440 (hex).
Reading the GPIO Data
MOV DX, 440: GPIO Address
IN AL, DX: Read the data into AL register
Writing the GPIO Data
MOV DX, 440: GPIO Address
MOV AL, XXH: Output data value “XX” OUT DX, AL
bit0 = GPI(O)0
bit1 = GPI(O)1
bit2 = GPI(O)2
bit3 = GPI(O)3
bit4 = GPI(O)4
bit5 = GPI(O)5
bit6 = GPI(O)6
bit7 = GPI(O)7