Port B

GPIO Name	Peripheral	Alternate
PB 00
PB 01
PB 02	Push Buttons	EXTINT_6
PB 03	Push Buttons	EXTINT_7
PB 04	USART	CTS
PB 05	USART	RTS
PB 06	Joystick	SCAN_4
PB 07	Joystick	SCAN_5
PB 08	Joystick	SCAN_6
PB 09	Joystick	SCAN_7
PB 10
PB 11