Hi,
On 10/26/2011 07:46 PM, Werner Almesberger wrote:
If you want to aggressively bring down the cost, you probably
have to get rid of the NOR. A 1 MBytes serial Flash is about
1 USD at Digi-Key, about 10 USD cheaper than the huge NOR.
Is that NOR flash really so expensive? Adam? Wolfgang?
I guess 1 MB should be enough for a fixed loader that pulls the
rest from the memory card.
No no. We keep everything on the internal flash. I do not want
involvements with low-level debugging of the memory card protocol
idiosyncrasies (and there are many) coupled with users deleting the
wrong files or formatting the card with unsupported filesystems.
Serial flash might be doable (even for XIP) with some FPGA design work
though.
Also, there might be no memory card and only Ethernet in the end. That
would even be preferable if possible without blowing up the cost.
* Memory card. Updates are via files on the memory card.
You'd still have JTAG and probably also USB storage.
I do not believe USB storage will ever happen. JTAG isn't for end users,
and will not be included in the package in order to reduce cost.
(We'll keep the same programming connectors as on the M1 though)
* Audio: the Artix-7 FPGAs now include ADCs, so we can get away with
at most an op-amp on the board. Only internal microphone.
So, line in but no line out ?
Yes.
Maybe even consider adding more USB host ports - also for
future M1 revisions. As USB stack functionality grows, so
will the number of peripherals.
Perhaps a third one for the keyboard + mouse + MIDI use case, but that's
about it - and assuming it can be done cheaply. I do not expect USB
stack functionality to grow a lot because this work is painful and no
one wants to do it.
It's not quite clear to me how you want to position the device.
If it's for M1 developers, they'd probably want more M1 features.
If it's intended as a cost-down replacement of M1, that may work.
If it's for FPGA enthusiasts, you can probably cut off some more
fat.
It is an entry-level M1, which is all of the above.
S.
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