Reads the values of all ports in the input settings at once.
Included in mwx library 0.1.4 or later
Reads the values of all ports in the input settings at once.
The values are stored in the order of DIO0 ... DIO19 from the LSB side. DIO19 are stored in this order.
The pins on the HIGH side are set to 1 and the pins on the LOW side are set to 0.