T
Tom Becker
Guest
I'm new to this, and momentarily baffled.
Some time ago, I bought an inexpensive programmer to work with PALs; it
worked fine for that project. Today, I'm working with Lattice GAL22V10Ds
and find that the programmer can't write to them, despite the
documentation's claim that it handles GAL22V10 and GAL22V10As, although it
can read and verify parts programmed elsewhere.
The programmer manufacturer says that the timing table is different for the
D-suffix part. They say their programmer "... can write the left 32 columns
of data to GAL22V10D, [but] the right 8 columns can not be written by using
GAL22V10A's timing table." That might be so, but _I_ can successfully write
to GAL22V10Ds using GALBlast.exe, a simple home-built parallel-port adapter,
and two power supplies. GALBlast reads the PES to determine at least one
timing parameter and displays the programming voltage that the part needs.
I assume the programmer does the same, but it merely erases the part,
apparently can't write and, of course, fails to verify.
My current project is back on track, but I'm concerned that I don't
understand something fundamental here. Does someone have a better
understanding of why this might be so?
TIA.
Tom
Some time ago, I bought an inexpensive programmer to work with PALs; it
worked fine for that project. Today, I'm working with Lattice GAL22V10Ds
and find that the programmer can't write to them, despite the
documentation's claim that it handles GAL22V10 and GAL22V10As, although it
can read and verify parts programmed elsewhere.
The programmer manufacturer says that the timing table is different for the
D-suffix part. They say their programmer "... can write the left 32 columns
of data to GAL22V10D, [but] the right 8 columns can not be written by using
GAL22V10A's timing table." That might be so, but _I_ can successfully write
to GAL22V10Ds using GALBlast.exe, a simple home-built parallel-port adapter,
and two power supplies. GALBlast reads the PES to determine at least one
timing parameter and displays the programming voltage that the part needs.
I assume the programmer does the same, but it merely erases the part,
apparently can't write and, of course, fails to verify.
My current project is back on track, but I'm concerned that I don't
understand something fundamental here. Does someone have a better
understanding of why this might be so?
TIA.
Tom