MC9S08SH8CTG Datasheet, PDF (32/341 Pages) Freescale Semiconductor, Inc – HCS08 Microcontrollers

Chapter 2 Pins and Connections
When an on-chip peripheral system is controlling a pin, data direction control bits still determine what is
read from port data registers even though the peripheral module controls the pin direction by controlling
the enable for the pin’s output buffer. For information about controlling these pins as general-purpose I/O
pins, see Chapter 6, “Parallel Input/Output Control.”
The MC9S08SH8 devices contain a ganged output drive feature that allows a safe and reliable method of
allowing pins to be tied together externally to produce a higher output current drive. See Section 6.3,
“Ganged Output” for more information for configuring the port pins for ganged output drive.
NOTE
To avoid extra current drain from floating input pins, the reset initialization
routine in the application program should either enable on-chip pull-up
devices or change the direction of unused pins to outputs so they do not float.
When using the 8-pin devices, the user must either enable on-chip pullup
devices or change the direction of non-bonded out port B and port C pins to
outputs so the pins do not float.
When using the 16-pin devices, the user must either enable on-chip pullup
devices or change the direction of non-bonded out port C pins to outputs so
the pins do not float.
MC9S08SH8 MCU Series Data Sheet, Rev. 3
28
Freescale Semiconductor