[Oberon] FPGA RISC memory interfacing

[Andreas Pirklbauer]

    > I noticed that Oberon System frequently freezes on one Pepino which we
    > have. I have not identified any pattern. Sometimes it works for days, and
    > sometimes it freezes after a mouse click on a command like the Hilbert curve.

It could also (potentially!) have to do with module unloading. If module Hilbert
overwrites a previously released module block, which is however still referenced
by other loaded modules or data structures (e.g., via type references or procedure
variable references), the entire system may become unstable at that moment
(recall that FPGA Oberon is inherently unsafe with respect to module unloading).