Best low cost uP for full Linux

I will be interested to hear what you come up with. The USB host, memory, etc requirements say to me "just buy a tiny form factor PC" but any other alternatives would be quite interesting.

Some of the smartphone chips would probably do everything but the ethernet, though there are of course ways to add that.

That would be an obvious choice if one was after a small Linux box. However, this is going to be part of a product and, as such, there is no way to include a small PC in it. My build cost needs to be in the $100 (USD) range at most.

Since the other part of the design will have a large Xilinx FPGA the right approach could very well be to use Microblaze and implement the Linux subsystem that way. Frankly, to me it seems like it would be using an expensive FPGA for the wrong purpose. You still need the SDRAM, FLASH and any supporting I/O bits. So, the only "savings" would be not having to buy a separate processor. If it is true that something like that '5329 can be had with a MMU, then pricing for the processor might be in the $15 to $20 range. I'm not sure that it makes sense to implement Microblaze and use-up valuable high-speed FPGA resources to save twenty bucks. But I could be wrong...

-Martin

The Atmel AT91RM9200 has a lot of the listed features, I know it has MMU, USB HOST (1 or 2), 10/100 Ethernet, SPI, 3/4 Serial, I2C. It has some support for FLASHes, check atmel site for details, they're not all in my head at this time. :-) While you're there, check the other ARM9 chips as well.

This is a bit over your specs and maybe your price, but if you aim only a few units or if it's a personal project it might be what you're looking for:

TI OMAP3 dev-board with 128mb RAM, 128mb Flash, lots of peripherals for just ~~ $150. Runs linux of course.

Nils

I actually just had a Freescale rep in yesterday afternoon, and he pointed me at an extremely interesting new widget. It's the MCF5445x (0

d me at an extremely interesting new widget. =A0It's the MCF5445x (0

In what way is this over the OP spec? It doesn't have ethernet or expansion bus as such (it has an unpopulated expansion connector with various peripheral signals on it).

Peter

How large is your FPGA?

With the AT91CAP9 you can have a dedicated bidirectional interface to an FPGA which then can be integrated into the built in 500k gate metal programmable logic block. Only limitation I can see is that you support 256 MB SDRAM/Mobile DDR.

The 256 MB limitation exist in most AT91 chips, but some chips like the AT91SAM9263 and the soon to be available AT91SAM9G40 supports dual buses. If you plan to have a large LCD (VGA or more), then the dual bus might be desirable anyway.

m escribió:

Have a look at NetDCU10 and similar products from

Hi Martin,

low cost and full MMU support always rings an ARM9 bell with me. Ulf has mentioned a couple devices from Atmel, there is also a LPC3250 from NXP. Some useful links to data sheet and evaluation board for that device can be found on the lpc website

An Schwob

Several parts in the Atmel AT91SAM9 series seem to match your requirements.

This design is using one of the larger Virtex 5 chips (also considering Stratix).

I'll have a look at the AT91CAP9 and see what I can determine.

I calculated that a Microblaze with the desired features would consume about 10% of the FPGA, 15% at most. That's not too bad. I would imagine that Nios would be about the same.

The only downside with Microblaze/Xilinx is that there is no USB core. You have to license it from a third party for about US$ 15K. A deal breaker unless the application is for very high volume (which isn't our case). Still, you can use external USB solutions from Cypress or FTDI and make it work.

-Martin

Hi,

You can only get full linux on MicroBlaze today. (If you define "full" as

Göran