Leonard DelVecchio

inability to set PTA4

Discussion created by Leonard DelVecchio on Oct 26, 2006
Latest reply on Feb 12, 2007 by Alban Rampon

I am attempting to simultaneously learn how to use a microcontroller and regain my long forgotten and limited knowledge of C. This exercise is in anticipation of an up-coming project using an HC08 with CodeWarrior. Not having any hardware I am working with “full chip simulation” both employing PE and not. The CPU is MC68HC908QB8.

My problem is as follows:

I am trying to set three pins on the PTA port so I can read them as if they were input (I understand that in this case I am only reading the last write). These pins are PTA3,PTA4 and PTA5. 

Regardless of how I try to set the pins, only PTA3 and PTA5 respond. Can anyone tell me why I cannot set PTA4? 

I am confident that OSC2 and KB14 ( which share the pin) are disabled, however, I am confused about AD2.

Thanks in advance.