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FZOVK's avatar
FZOVK
Icon for New Contributor rankNew Contributor
5 years ago
Solved

Arria 10 can't read from flash via Generic Serial Flash Interface

We have an Arria 10 FPGA connected to a Micron MT25QU256 flash. The FPGA is able to obtain its program from the flash and configure correctly on power-up. We are trying to use the Generic Serial Flas...
  • FZOVK's avatar
    FZOVK
    5 years ago

    Hi John,

    1) We are using the GSFI, but gsfa_asmi_access_granted_reg is a register in the Serial Flash Loader.

    2) Yes, that is correct, we wanted to start out by seeing the device ID read work correctly before moving on to reading and writing the flash memory.

    We have the baud rate divisor set to 0x10 and we have seen the SPI pins behave as expected.

    We were able to get everything to work once we removed the Serial Flash Loader from our design, leaving the GSFI directly connected to the SPI interface. I don't think we will need any further assistance; thank you for your help.

    Frank

JohnT_Altera's avatar
JohnT_Altera
Icon for Regular Contributor rankRegular Contributor
5 years ago

Hi,


Could you provide me the step that you used to read the data and what is the setting used in the GSFI CSR Register?


FZOVK's avatar
FZOVK
Icon for New Contributor rankNew Contributor
5 years ago

Hi John,

Thanks for your quick response. Our process for attempting to read the flash device ID is as follows:

1) Set bit 0 of the "gsfa_asmi_access_granted_reg" register to 0 in order to give the GSFA module access to the flash.

2) Write 0x0000489F to the Flash Command Setting Register (register offset 0x7).

3) Write 0x00000001 to the Flash Command Control Register (register offset 0x8).

4) Read the Flash Command Read Data 0 Register (register offset 0xC).

We are getting all zeroes from that read operation at the end, even though we can see (by probing the flash data output line) that the flash is responding properly with the device ID. Also, in case this is relevant, we have connected the following pins between the Serial Flash Loader and the GSFI: atom_ports_dataout, atom_ports_dataoe, atom_ports_datain, atom_ports_dclk, atom_ports_ncs, atom_ports_oe.