Cyclone conf flash - 25p10 !

"Luis Cupido" wrote in news:newscache$0vhemi$3um$ snipped-for-privacy@newsfront4.netvisao.pt:

This is very interesting since the configuration roms are expensive compared to typical SPI flash. I noticed that Lattice is pushing the fact that they can configure using cheap standard SPI flash.

Do you use the 25p10 A version. Have you tried SST parts?

Then SOMETHING must be different ?

... and you will see Xilinx have also hopped on this bandwaggon, with their newest Spartan 3E's - much hoopla about std SPI and also NOR flash loader options. It cost them ~3 pins, to select the vendor/state engine for a given SPI memory. Not before time, but it will mean Altera have to step into line as well, and remove any 'deliberate' hurdles that might have found their way into their tool flows ( if that's really what's occured ? )

-jg

ST Micro's flash devices can be used instead since they are drop in replacements, correct? They are much cheaper.

The ones I use are the 25P10A from ST. (25P10AV-ST)

lc.

Hi,

Right :) ... but only Quartus II knows how to check that

One hypothesis is that the EPCS devices come from altera with something on memory to tell that they are from altera. and Quartus II also writes something to keep this thread going. Would that be the trick ?

That was what I would like to know ;) I'm sure I'm not the first one to use the 25P10A

Anyone can use them, just make an RBF file on quartus and send it to the 25P10A using other software than quartus.

lc.

Correct.

Only Quartus II refuses to program them, but you can load them with external prog software.

lc.

You could test that idea, by using your other SW to read back 100% from a Altera tagged one, and copy that into the ST one, then see if Quartus can still spot the difference... ?

-jg

Sorry, my bad. I know I have programmed them using the ASMI interface in NIOS (is this what you are referring to by external prog. software?), but I haven't tried using the BB cable directly to the flash device.

On the note that it must be shipped with something special in it.. .Altera clames the device is shipped with the memory all reset to FF's... where could they possibly store something? Jim's test definitely sounds like something interesting to try. It's a shame because I can't use anything more than a 4 Mbit flash device for configuration since Quartus only supports 1 and 4 (for me at least). I have a 32-mbit ST Micro flash device that I'm using as secondary flash holding user-code, but I can't seem to get it working as a primary configuration device.

Maybe the $12 increase in price over the STM counterparts is actually something functionally different rather than a re-label :)

Have you opened a case with Altera ?. That's a reasonably mainstream use of the config, and one they should be keen to support this obvious usage.

-jg

Apparently the difference has to do with the WP pin!

Regards, Mark

Mark McDougall wrote in news:4320d893$0$14486$5a62ac22 @per-qv1-newsreader-01.iinet.net.au:

Mark, Do you want to comment further?

What are you referring to Mark? The WP pin on the ST micro device is active low, and it's held at Vcc on the EPCS4 Config device (you are supposed to keep it at Vcc I mean).... meaning no write protect. This is essentially the same, correct?

I just tried configuration with an ST Micro 4 Mbit device and it didn't work :( It was the M25P40.

" snipped-for-privacy@gmail.com" wrote in news: snipped-for-privacy@o13g2000cwo.googlegroups.com:

I think there is a difference between an M25P40 & M25P40A. I'm not sure since we moved to SST for serial flash (for other purposes).

Hmmm, this info came from my colleague when I mentioned this thread in passing. He recalled that there was a difference with the WP pin...

...however we've just checked the 25P10 and EPCS1 datasheets and they do indeed look pin-compatible w.r.t. the WP pin, so we're at a loss to explain.

Sorry 'bout the red herring...

Regards, Mark

Do you think the A version works? I can't get an SST part from Digikey, my only source, which means I'm out of luck :(

I just can't seem to grasp that one of these parts costs $17....

" snipped-for-privacy@gmail.com" wrote in news: snipped-for-privacy@g47g2000cwa.googlegroups.com:

I have no idea which of these parts might work. The SST parts are pin compatible but have different IDs. They probably cannot program from quartus but they might read OK.

Looking at the *.pof for a Cyclone configured to load from an EPCS4, the string EPCS4 is included at the start.

I'm not sure of why I think this, but I've an idea that the devices check the device ID at the start of config, although this might be wrong.

If this is the case you'd have to use a device with the same ID.

Nial.

------------------------------------------------------------- Nial Stewart Developments Ltd FPGA and High Speed Digital Design

Can you just change the ID in the POF file manually?

Folks,

The 25P10A from ST do work fine.

Yes the *.pof knows what is the target device.

That info on the *.pof file is for the programmer soft-module to know how to program, and that doesn't go into the device.

The Cyclone device check the device ID to know how much data it may have to load, just that... I think.

I can't tell what ID's are recognized by the Cyclone load engine... but at least the ones corresponding to the EPCS1 and EPCS4 are for sure.

The bottom line is still, ST25P10A has the exact same ID as the EPCS1 and quartus II still fails to load them. However is a fact that once programmed (by other means) Cyclone devices do read them without trouble.

Luis C.