int
_ao_serial0_pollchar(void);
+uint8_t
+_ao_serial0_sleep(void);
+
void
ao_serial0_putchar(char c);
int
_ao_serial1_pollchar(void);
+uint8_t
+_ao_serial1_sleep(void);
+
void
ao_serial1_putchar(char c);
int
_ao_serial2_pollchar(void);
+uint8_t
+_ao_serial2_sleep(void);
+
void
ao_serial2_putchar(char c);
int
_ao_serial3_pollchar(void);
+uint8_t
+_ao_serial3_sleep(void);
+
void
ao_serial3_putchar(char c);