Hard Reset of IXP1200 over PCI?

[Scott C. Karlin]

I'd like to be able to perform a hard reset of the
IXP1200 over the PCI bus.  Most of the documentation
seems to indicate that I cannot do this.  However,
the IXP1200 Programmer's Reference Manual seems to
indicate that it might be possible (but not allowed).

Section 4.7.13 IXP1200_RESET indicates that the
IXP1200_RESET register can be read and written
from offset 0x7C.  However, the paragraph directly
above says that "PCI devices must not write to this
register."

What happens if I do?  (I assume that the IXP1200
will reset and clear the PCI registers including the
BAR set by the host machine.  If I promise to put the
board back in the same place in the PCI memory map,
will everything be OK?)

Scott