Gpio7/vox (When Gpio7=VH, vox is active; else VL)
Gpio6 / sq
(When Gpio6=VH, sq is active; else VL)
Gpio5 / txon
(When Gpio5=VH, txon is active; else VL)
Gpio4 / rxon
(When Gpio4=VH, rxon is active; else VL)
Gpio3 / sdo
(Gpio3=VH or VL, it is the output register data in 4 wire control
Interface mode)
Gpio2 / int
(When Gpio2=VH, int is active; else VL)
Gpio1 / code_in / code_out
(Gpio1=VH or VL, it is the input/output code data)
Gpio0 / css_in / css_out
(Gpio0=VH or VL, it is the input/output CTCSS/CDCSS signal)
4.7.3.Port Description of Master Chip HS8851
IC level input under Man Down state
Battery capacity detection
Switch of voice receiving / alert tone