Microcontroller selection

"Ravishankar S" a écrit dans le message de news: f5qai5$d4i$ snipped-for-privacy@news4.fe.internet.bosch.com...

If you want an embedded Linux then you will definitively need more than 1Mo of Flash and 64Ko of RAM. What about using a ready made low cost COM module, like

Yours, Robert

By the time you are going above 512K flash, it is normally much more cost effective to have an external flash device on a databus. You are also going to want more ram - there is very little reason for having USB2 and 100 Mb Ethernet if you don't have the space to do something with it. So unless you have very specific reasons for wanting memories on-chip, look for something with an external databus.

An Atmel AVR32 (AP7000) will do what you want if you accept external flash and the USB 2.0 is a device and not a host.

You will not find an FPGA with built in flash.

thanks guys, for the hints!

the reason for internal flash is: makes the board smaller and simpler (no memory interfacing) and reduced pin count the reason for linux is: low cost, drivers for ethernet and USB built in and already present know-how (in writing drivers)

i have not looked into AP7000 yet. but point not to forget in controller selection is: tool support. how are the tools support for AVR32 ?

-> build tools: i suppose GNU must have been already ported../ Atmel has AVRStudio ..integration..?

-> debug tools -> Any low cost wigglers available..(gdb support?)

-> OS: linux support/ does atmel provide any drivers/RTOS

Intended application: The application is simple debug device which provides a better performance and ease of use than Wiggler. I suppose a microcontroller with built in support for configurable I/O should help here.

Kind Regards, Ravishankar

else)

serial

Wrong. Many vendors make FPGAs with built-in flash, for instance refer to the Xilinx Spartan 3AN.

---Matthew Hicks

I'm not aware of a single-chip Linux solution. For any useful Linux You need more RAM than you've specified. Even uCLinux "specifies" minimum 1MB ROM/flash and 200KB RAM.

Actually, whatever isn't used for the FPGA's bitstream can be used to store anything else and is acessable to the FPGA logic at runtime.

---Matthew Hicks

Microcontrollers with glueless memory interfaces are often quite simple, but external memory certainly adds to the pin count and board size.

You might find support in other systems, such as freertos, or using separate stacks like lwip.

Linux and internal memories do not go together, as a general rule. The only exception I know of is from Axis:

Linux is way over the top for such an application, IMHO.

That's flash for the configuration of the device, not flash memory for storing program code. You can store initial values for ram blocks in the flash, but it's of a size appropriate for a small bootloader rather than a full application or os (especially if he is planning on using Linux).

mvh.,

David

I'm not familiar with the details (I'm an Altera fan), but you are still likely to be far from the required flash size for Linux (unless you are seriously underusing your fpga).

mvh.,

David

The Altera MAX-II has flash available to the FPGA core logic. However, it's not very large and getting Linux (or even NIOS) to run on the MAX-II would be somewhat difficult. But I guess we'll see more FPGA's with combined configuration and user flash in the future.

Petter

I agree it's small (at most 11Mb), but the post I responded to said FPGAs didn't offer this. I just wanted to correct the error in case someone who had a less memory intensive project read it and ruled out using FPGAs.

---Matthew Hicks

"Ravishankar S" skrev i meddelandet news:f5qt8b$vca$ snipped-for-privacy@news4.fe.internet.bosch.com...

There is a free gcc toolchains supported by Atmel. Eclipse based AVR32 Studio IDO Debugging through same JTAGICE Mk II as used with the AVR. Dev kit (linux capable) for less than $100 has 32 MB of SDRAM and 16 MB of Flash.

Sounds more like [tick box laziness] to me.

You need to decide how much resource your task needs (without the OS) and then find some Eval boards, and actually try them.

If you want to skip USB/Ethernet code, (that's ok) then find Eval kits with that portion already working in their examples - what you really want is not linux, but working peripheral libraries.

and you think you need Linux ?!

This for example, would be a good starting point :

(Just $49.)

-jg

Tedious it may be be, but it is a required learning challenge for the designer. If you don't want tedious on occasion, you chose the wrong line of work ;)

That said, there's nothing wrong with asking for suggestions, but ultimately you will have to choose; and unless you have been through the tedium of locating and choosing a processor/controller you will be ill equipped for the task.

Cheers

PeteS

If you have Linux running, then you could conceivably run OpenOCD in the box.

thanks group, once again for the hints:

that narrows down my search, since there are a huge number of microcontrollers out there.

linux: now it seems overkill for the application. that's now for sure..

AP7000 is not suitable: it has way too many peripherals..and its intended for multimedia low-power apps, but AVR32UC - microcontrollers seems to be a perfect fit. Im yet to look at the ST micro.

The configurable I/O pins are important since it will deal with JTAG pins.

Also, i think the trend is towards a single chip solution: look at SoC's. it may be good from learning point to interface external devices, but for prototying its better to have everything on chip. It is also good from EMI perspective (Automotive).

K> > Hello group,

else)

Linux.

serial

"Ravishankar S" skrev i meddelandet news:f5tibc$9fb$ snipped-for-privacy@news4.fe.internet.bosch.com...

If you want high speed USB (480 Mbps), your selection is limited. If you accept Full Speed USB (12 Mbps), then your next selection criteria should be high speed DMA driven synchronous serial peripherals.

The Atmel synch serial port peripherals generally run as fast as the CPU core.

Note that the AP7000 series has high-speed (480 mbps) USB, whereas the UC3 series has only full-speed (12 mbps) USB.

Leo Havmøller.