Eriol status, 5th february 2000
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The design of the Eriol control logic has progressed steadily during january. Entering february
the first fullscale test simulation of the control logic is about to begin. Following this
a shorter period for correcting any logic errors must be expected.
After having verified the logical correctness of the control logic it will be time for a fullscale
timing simulation of the logic. Hopefully this will prove what I already believe - that the timing
of the control logic will hold.

However, the Eriol project has also run into some trouble, which may delay the project. The
entire Eriol control logic is to be put into an FPGA logic chip. The size of the
logic asks for an FPGA of some logical capacity. Unfortunately the development system that I
have access to cannot cope with such big FPGA designs, as it is not a full development system,
but rather a smaller (and cheaper) version.
Three solutions exist and are under evaluation. The first is to get hold of a full development
system. This will most likely be very expensive and I don't think I can convince the University
that it has to pay up (unfortunately).
The second solution is to break the design into two separate and smaller FPGA chips. This will
give access to enough logic space to allow an implementation. However, it will give more delay
in the hardware as signals has to pass in and out of the FPGAs, and be a lot more expensive due
to the extra FPGA.
The third solution is to find another logic device for which the University has a development
system which can handle the big design.

Currently the solution being worked on is the second. I'm now working on logically splitting the
logic into two FPGAs. Together with this a redesign of parts of the logic will take place as to
minimize the number of signals having to go from one chip to the other.
Unfortunately this use of two FPGAs will put just about an extra £20 on the production price :(
The final product price is still undefined...

The first prototype board, first expected at the end of february, will without doubt be delayed
from the afore mentioned problems. When the first prototype board will exist is now an open
question, but the delay should be no more than a month.


Yours sincerely

Thomas Graff Thøger,
TigerTronics