SPI only, or NVCM also?

[Hugh Aguilar]

I haven't read though this section of the forum, so please pardon me if this question has already been answered.

Does your iCE40HX8K-EVB allow programming through NVCM, or only SPI?

SPI can be written to many times, so it is for development. NVCM is write-once so it is for the production version. The problem with SPI is that it can be read, and there is a tool available for decompiling this into Verilog, so the design can be reverse-engineered.

What I would like to do is get a processor running on the HX8K. This would be a superset of the 65c02 ISA (a few extras, such as multiplication and access to RAM beyond 64KB). Being 65c02, my compiler for the NEO6502 could also generate code for this. And of course I would have a heartbeat timer, that the NEO6502 sorely lacks!

I don't want to have my design in SPI though, because it would just get reverse-engineered. Red China is the primary problem, but there are bad actors in the Western world too. I don't want to put a lot of work into this, then find somebody selling an HX8K board that does something useful and uses my processor design and my compiler. I'm not an altruist --- I don't want to help people make money.

[LubOlimex]

I don't see why it shouldn't allow NVCM since the main chip has that feature. All HX series (like iCE40HX8K-CT256) have NVCM. It is internal memory in the chip. Refer to Chapter 4 of this document:

http://www.latticesemi.com/view_document?document_id=46502