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About ntallen

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  1. ntallen

    Nexys4 Spi Flash

    I have this working using XPS. I agree completely with sbobrowicz: you need a STARTUPE2 primitive in order to drive the clock. On that primitive, you need to drive the USRCCLK0 (with the clock signal you want to send to the flash) and you need to drive USRCCLKTS to '0' to enable the clock output. Within XPS, this is handled just by selecting the 'Use STARTUP Primitive' option. In my experience, getting the clock to the part was only the first hurdle, but it is clearly an important step.
  2. ntallen

    Nexys4 Spi Flash

    I found working with a logic analyzer to be very helpful in getting my application to work. As Sam suggests, making sure you can at least control the CCLK is a very important first step. After that, you have to work your way up through the protocols required to talk to the device, which are non-trivial.
  3. ntallen

    Nexys4 Spi Flash

    I did get this working, so don't give up hope. I am using XPS in my design, so I can tell you how I got it to work, but if you're doing something different, that might not help so much. Are you using XPS? I will try to follow up tomorrow with more details.
  4. ntallen

    Nexys4 Spi Flash

    In section 3 of the Nexys4 manual, it says: An Artix-7 100T configuration file requires just under four Mbytes of memory, leaving about 77% of the flash device available for user data. I spent some time trying to figure out how to accessthat available space but was thwarted by the fact that the configuration clock output at E9 is dedicated for use during FPGA configuration, so I can't drive it in my design to access the flash. Is there a work around for this that would actually make it possible to access this extra space?