Datasheet

Chapter 3 Port Integration Module (PIM9E128V1)
MC9S12E128 Data Sheet, Rev. 1.07
160 Freescale Semiconductor
Figure 3-49. Illustration of I/O Pin Functionality
Figure 3-50 shows the state of digital inputs and outputs when an analog module drives the port. When the
analog module is enabled all associated digital output ports are disabled and all associated digital input
ports read “1”.
Figure 3-50. Digital Ports and Analog Module
3.4.4 Reduced Drive Register
If the port is used as an output the Reduced Drive Register allows the configuration of the drive strength.
3.4.5 Pull Device Enable Register
The Pull Device Enable Register turns on a pull-up or pull-down device. The pull device becomes active
only if the pin is used as an input or as a wired-or output.
PTx
DDRx
output enable
module enable
1
0
1
1
0
0
PAD
PTIx
data out
Digital
Module
Analog
Module
1
0
1
PAD
Digital
Input
Digital
Output
1
0
Analog
Module
Enable
Output
PIM Boundary