Best low cost uP for full Linux

I am trying to select a uP to build into an embedded device. Here are the requirements:

- Run full Linux with MMU support

- External bus support for more than 256MB of RAM, preferably DDR2

- Support for 64MB+ of NAND FLASH

- Support for 8MB of NOR FLASH

- I2C (2 ports ideal, one is OK)

- SPI

- USB Host x2

- 10/100 Ethernet

- At least two serial ports, four even better

- LCD interface highly desirable

- 16 to 32 available parallel I/O pins

- Expansion bus for external peripherals

- Low cost

Something like the Coldfire MC5329 would be perfect, except that this chip does not have a MMU and you are forced to use uCLinux, which I want to avoid due to the lack of memory protection and other limitations.

I'd appreciate a shove in the right direction.

Thanks,

-Martin

Reply to
m
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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.

Reply to
cs_posting

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

Reply to
m

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.

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Stef    (remove caps, dashes and .invalid from e-mail address to reply by mail)

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Reply to
Stef

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:

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

Nils

Reply to
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

Reply to
Rob Gaddi

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

Reply to
m

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

Reply to
Peter Dickerson

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.

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Reply to
Ulf Samuelsson

m escribió:

Have a look at NetDCU10 and similar products from

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. ARM9 based, comes with Linux 2.6 or Windows CE.

Reply to
Ignacio G.T.

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

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An Schwob

Reply to
An Schwob in the USA

[...]

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

Reply to
Eric Smith

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

Reply to
m

Hi,

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

2.6 kernel with MMU) NIOS only support uclinux today.

Göran

Reply to
Göran Bilski

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