I have a M68KIT912DP256 evaluation board for the MC9S12DP256
microcontroller. On the evaluation board there is a set of switches
that I would like to read and send to port B (which is connected to a
set of LED's). When viewing the memory using CodeWarrior, the value of
the PTIH register contains the value I expect, and everything goes as
desired. As soon as I now write a value to port B (this may be just a
constant), and  at the same time, more then 5 bits in PTIH are 'on'
(meaning 0), the whole process stops, while the command window in
CodeWarrior continues to mention a change in frequency. What is it
that I do wrong? My initial settings are:

    DDRB  = 0xff
    PORTB = 0xff
    PTIH  = 0x00  
    DDRH  = 0xff
    PTH   = 0xff
    RDRH  = 0xff
    PPSH  = 0xff
    PIEH  = 0x00
    PIFH  = 0x00