Mesa Reccomendations for custom made servo drive

PCW wrote:

The Picoblaze and Microblaze are nice but for our purposes the
Picoblaze is too slow and the Microblaze is way too big and they are
both load/store (RISC) architectures which are quite inefficient when you have
lots of direct I/O.

I expected that answer. I was just shaking your strings a little. Couldn't resist, sorry

Also not sure if C makes much sense when you only have 2K of code space

It depends on how badly you need the 2K, and if you can spend the extra block RAM if handoptimized assembly is already pushing the 2K.
(with blockrams it's the same as with controller I/O pins: you think you have plenty but in the end you can always use a few more).

I am lucky enough to have to design for low volume production runs only. Several 100's, low 1000's. If software development cost over the entire lifecycle can be reduced by spending a few bucks more in the hardware BOM it is usually worth it. And the problem with assembler is that every few years you can do it all over again. Besides that: modern compilers are quite decent, which makes the C code space penalty significant only when the programmer has no idea what he/she is actually writing. Rubbish in, rubbish out.

Oh, more offtopic: I was positively surprised by the design of the 7i76. The guy who did that did a good job of making a piece of hardware that just works in an agressive environment, compared to many examples of hardware that works well on the lab bench but is troublesome in the real world, and he deserves a thumbs up.

Our code size constraints/blockram size issues are largely because
we like to keep as much as possible of the latest HostMot2 code working on our
oldest cards (Spartan2 based) at some point (especially with SSLBP)
we will need to expand to a luxurious 4K of instructions!
4K looks like unlimited space to us now

That is pretty amazing though a bit difficult to understand
with no comments and no symbolic constants, variables or labels

andypugh wrote:

[1] It was a British computer, so it ran programmes, not "programs"

Reminds me of the ZX Spectrum 48 and later the 128. That thing got me into electronics. Putting a shadow RAM over the ROM where a speedloader resided so I could very easily copy games (just load the RAM image and resume execution), making a NE555 based 'joystick' to get insane Daley Thomson supertest scores, etc. And then I blew an ULA again, dad angry.

I hope things like Arduino, Raspberry Pi, etc. will do the same for modern kids. Here in The Netherlands it is pretty hard to find people interested in developing electronics nowadays.

Stop fixing things for your kids.
..
..
When they hit eleven, give them a plaintext file with ten-thousand WPA2 keys and tell them that the real one is in there somewhere. See how quickly they discover Python or Bash then.

Mhuuuhahaha