Programming non-EPCS serial flashes?

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originally posted by mike desimone@Oct 20 2006, 10:17 AM

thanks for the responses, but i'm not looking for a drop-in replacement for an epcs; that configuration would still only allow a single firmware image.

has anyone heard anything from altera about the nios flash programmer supporting arbitrary flashes by allowing you to build your own firmware? failing that, does anyone have the source to the nios flash programmer firmware rom?

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Just a suggestion, considering the following:

Keep your AVR and an EPCS in which your store consecutively your 3 bitstreams.

Maybe it is possible to do the following:

- wire SPI programmation bus to your AVR and your EPCS, (in parallel)

- let the flash programmer access to the EPCS through SPI, as normally. During this programming phase AVR must be "tris-stated" on SPI lines.

- during boot, let the AVR override the SPI bus to initiate an SPI READ command to the EPCS , at the **desired ** offset location. This will set the current pointer in the EPCS.

- then remove AVR from SPI bus, and let the FPGA boot from this starting address. If you&#39;re lucking, (to be checked) , the FPGA will no rewrite the starting pointer (0 value) , just reading data from the current value. But I&#39;m not sure about that. You should have a look to EPCS boot sequence (active serial mode).

Once again, this has to be checked.

BR