$0020 constant P1IN
$0021 constant P1OUT
$0022 constant P1DIR
$0023 constant P1IFG
$0024 constant P1IES
$0025 constant P1IE
$0026 constant P1SEL
$0041 constant P1SEL2
$0027 constant P1REN
$0028 constant P2IN
$0029 constant P2OUT
$002A constant P2DIR
$002B constant P2IFG
$002C constant P2IES
$002D constant P2IE
$002E constant P2SEL
$0042 constant P2SEL2
$002F constant P2REN
$0018 constant P3IN
$0019 constant P3OUT
$001A constant P3DIR
$001B constant P3SEL
$0043 constant P3SEL2
$0010 constant P3REN