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Altera_Forum
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20 years ago

Nios II and separate WRITE_N signal to CFI Flash

Hi, It has been long time I played with Nios II, my first attempts were abandoned due to the project change. Now I am blessed with another project which would have a Nios II as a CPU candidate and...
Altera_Forum's avatar
Altera_Forum
Icon for Honored Contributor rankHonored Contributor
20 years ago

I seem to be having a problem with read_n being shared and write_n not. When I create a CFI flash component in my system, it generates the read_n as a shared signal (namely, a signal of the tristate bridge). With this setting, I am unable to use the flash (using the standard example memtest.c program, on the Stratix II s60ES FPGA).

http://forum.niosforum.com/work2/style_emoticons/<#EMO_DIR#>/unsure.gif

However, in the examples directory, if I look into the .ptf of the full_featured example, there the read_n of the flash is not shared but rather is a separate signal. Using full_featured as the .sof, I&#39;m able to successfully test the flash via memtest.c !

Has anyone encountered this problem ?

Is it possible to force SOPC builder to "un-share" the read_n signal of the flash ? I guess I can change the .ptf directly, but my change will be overridden by SOPC builder when I generate the system.