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    How to access Micron MT25Q nor flash

    Greeting,

    I have a project that create QUAD SPI controller for MT25QU device. I am able to access to all register of the flash, but not able to read back data from the memory. here is my procedure (assume that i am already in quad mode)

    1. Write Enable x06h
    2. Write Extended address xC5h + 00 (flash region 0)
    3. Read Memory (quad input/output fast read) xEBh + 000_0000 (24bit address)

    I am not getting right result back. I know at the begining of the flash my data is 0303, but I got back is 0xFF.

    I looked at wave form, and my wave form is closely follow Micron datasheet.
    2 clk cycle cmd
    6 clk cycle address (only use 24 bits address and 2 bits for select flash region)
    10 clk dummy cycles
    4 clk read back ( i have 2 flashes, and read 16bits from each flashes).

    Thanks

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  2. #2
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    Re: How to access Micron MT25Q nor flash

    Hi,

    A lot of text, no clear question, not much we can verify...

    Please give
    * (a link to) the datasheet
    * your code
    * the scope picture
    * schematic
    * register contents (maybe the memory device needs some setup, or there are some write/read protections active)

    Klaus
    Please don´t contact me via PM, because there is no time to respond to them. No friend requests. Thank you.



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  3. #3
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    Re: How to access Micron MT25Q nor flash

    Thanks for replying to the thread.
    My question: how do I access to Micron spi flash memory? Is there any procedure that I need to follow?
    datasheet: https://www.micron.com/products/nor-...12abb8e12-0sit

    the device is already set up in quad mode and verified with manID, and other flash registers.
    status register: 0x00
    flag status register: 0x80
    volatile configuration: 0xFF
    Enhanced volatile configuration register: 0x7F

    Waveform:
    -- Read manID waveform
    Click image for larger version. 

Name:	mandID.JPG 
Views:	6 
Size:	73.6 KB 
ID:	156838

    -- try to read data but could not get right return
    Click image for larger version. 

Name:	read_mem.JPG 
Views:	6 
Size:	163.8 KB 
ID:	156839


    Thanks
    Ken



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    Re: How to access Micron MT25Q nor flash

    It's more likely that the preceding write didn't succeed.

    It's not clear how the waveforms (apparently from a simulator) are related to your microprocessor hardware.



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    Re: How to access Micron MT25Q nor flash

    Hi FvM,

    I program flash with working FPGA image. the first data at 0x0000_0000 address is 303A. I tried to read data at that address and getting 0xFF.
    the wave form is the actual pin out at the FPGA. So i would assume that the FPGA did actually sending out these signal to the flash.

    Ken



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