Acnodes FES 8730 - Manual (Page 71)

Note1:
The N has 8 bits. Only bits 4,5 are programmable.
" 1" means that the bit is programmed to input.
" 0" means that the bit is programmed to output.
User have to keep the value of Bit0~Bit3 and Bit6~7, to prevent from effect the status of COM Port.
Ex:
N=30h=00110000b
Bit7 Bit6 Bit5 Bit4 Bit3 Bit2 Bit1 Bit0
No use No use LED1
as output
LED0
as output
No use No use No use No use