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Honored Contributor
Honored ContributorCyclone II Serial Config
I'm having a rather odd problem and I was wondering whether anyone else has experienced it.
I'm using an M25P40 serial prom with an EP2C20. Standard setup, in fact we reused the schematics from a previous project and repinned the FPGA. The only difference is that it's a Cyclone II instead of a Cyclone part. We've only built 4 boards and they are all flakey. The problem is that the proms are mysteriously unprogramming themselves during normal operation. That is, the Cyclone II won't configure until the prom is reprogrammed. Sometimes the serial prom can't be reprogrammed and must be replaced. Any ideas? Thanks for your help. Leslie41 Replies
Altera_ForumHi stephenzhou,
it really doesn't matter. The pullups are just, i would say, nice to have. :cool: You can bypass them an connect those pins directly to VCC if you want to. (When you don't have the place or its to expensive). --- Quote Start --- so did you use M25P10? M25P80? M25P16 for EPCS1? --- Quote End --- I always used the M25P40 as replacement for the EPCS4 because there was no need for smaller parts. I'm not really sure, but i would say the M25P10 is comparable to EPCS1. I would advise you to compare the datasheets of the M25Pxx devices with the datsheets of EPCSx devices, then you will see what you need. (I hope so!) Christian- Altera_Forum
thank u for your great reply,
sorry for my poor net. so did you use M25P10? M25P80? M25P16 for EPCS1 %%%? and what u said M25p40 EPCS4 C-----------DCLK D-----------ASDI Q-----------DATA S-----------NCS W-----------VCC (With pullup) HOLD-------VCC (With pullup) VCC--------VCC VSS--------GND with pullup use 10K ohm?or 1K ohm? - Altera_Forum
Hi stephenzhou,
the M25P40 is one to one pin compatible to the EPCS4 Device. So if you wired the Configuration Device right for the EPCS4 device then you can replace it directly with M25P40. This works well ( I used it with Cyclone EP1C20, Ep1C12, Ep1C4 and with Cyclone II EP2C8). M25p40 EPCS4 C-----------DCLK D-----------ASDI Q-----------DATA S-----------NCS W-----------VCC (With pullup) HOLD-------VCC (With pullup) VCC--------VCC VSS--------GND The Pins W and /Hold are used for some special featurees of the M25P40 device. I never tried the EPCS4 to support this features like Hold and Writeprotect, but i would think it can support such things even if it is not mentioned in the datasheet. When you want to use the M25P40 with *.jic You have to chosse the EPCS4 in the Configuration dialog. Regards Christian - Altera_Forum
M25p40 EPCS4
C-----------DCLK D-----------ASDI Q-----------DATA S-----------NCS W-----------???? HOLD-------???? VCC--------VCC VSS--------GND and what did "w" and "hold" connect when we use - Altera_Forum
Hi Ckirsche, I use (Quartus II -> File -> Convert Programming Files) but just find the configuration device is EPCS6,and if I use M25P40,how can I use this ?
and can you give me a discription about M25p40's pins connect(MAP)? just for M25p40 EPCS4 C ？ D ？ Q S …… thank u very much! - Altera_Forum
hi Ckirsche,I want to know about is ST M25P40 SPI flash just suit for EP2C8?can M25P40 Support for all the Altera's FPGA?
Thanks - Altera_Forum
We use here the M25P40 Devices with the EP2C8 without any problems on some hundreds of boards. So I think there is something wrong with the wiring of the Pins on your boards. Do you have access to the JTAG pins of the Cyclone II? So you can try to program the M25P40 using a *.jic Files via JTAG(Quartus II -> File -> Convert Programming Files)
Christian - Altera_Forum
Hi,
Is it possible to see any schematic of EP2c8 with ST M25P40? As I can see from datasheets CPLD is necessary to use this combination or am I wrong? Thanks Primoz - Altera_Forum
Hi,
I also use an ST M25P40 SPI flash with an EP2C8 in AS scheme, this without any problem. Did you check M25P40 SPI lines during normal operation (I mean after configuration) ? Maybe the M25P40 is chip selected in an unexpected way. Also ensure that M25P40 CS pin is pullup'ed. See M25P40 ST specs about power-on/power-down behaviour. Hope this will help :) . - Altera_Forum
Thanks for the quick reply.
What, you don't read minds? ;) The serial config device is set up for AS programming. Both MSEL tied low on the Cyclone II and a separate JTAG connector. Wiring, pull-up and pull-down resistors are all correct. Switching to the Altera part was my first guess, too. Not sure why we are using the other in the first place. I fired off an email suggesting the EPCS4 at about the same time as I wrote the first post about my problem. I had read the documents you listed - and read them carefully hoping I'd overlooked some tiny detail. Nada. It's odd only because we've used the M25P40 in the exact same circuit on several designs without a problem. I'll post a follow-up after the boards come back from the field and I can actually look at one.
