Aaeon PICO-KBU4 User Manual page 101

The following is a sample code for 8 input
.MODEL SMALL
.CODE
begin:
mov cl,01h
mov al,80h
call CT_I2CWriteByte
call Delay5ms
mov al,00h
mov cl,20h
call CT_I2CWriteByte
mov cl,22h
call CT_I2CReadByte
;Input : CL - register index
Appendix D –DIO 88