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Nor Flash

rbork
New Contributor

I am using a Cypress S25FL512S with a Xilinx Zynq 7Z020.   This particular flash has a flash block protection method where a one time programmable bit in the flash Config Register forces the chip, upon reset, to boot up with all of flash protected from erase and programming.   You can disable Block Protection in the  flash by clearing three Block Protection bits in the Status Register.   I have verified that this all works as designed.

The problem I have bumped into is that once the flash chip is (permanently) in this block protect mode, the Xilinx Zynq BootROM can no longer properly read the flash on reset.  I have little visibility into the precise nature of the BootROM failure.   The BootROM puts a code of 0x0C into the REBOOT_STATUS register - indicating "Quad-SPI boot mode.   The BootROM is unable to find a valid header within the image search range."   It may well be that while the BootROM has support for this flash chip, it does not have support for the flash chip in this mode.

I am able to load code into the Zynq via the Xilinx IDE and run diagnostics to verify that the boot images are properly programmed into flash.   There is nothing wrong with the boot images.   People on my project have been building and programming boot images into flash for over a year.  This is a known and solid process.

I either need someone to tell me how we can get the Zynq BootROM to work with the S25FL512S with Block Protection enabled OR someone that can tell me that this cannot work, i.e. it is not supported by the Zynq BootROM.

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1 Solution
BushraH_91
Moderator
Moderator

Hello,

Thank you for contacting Cypress Technical Support, an Infineon Technology Company.  Xilinx boot process expects the Flash to be non-protected for Read access. It won’t issue an unprotect command, therefore the Flash should not be in read protection mode to be able to boot the Xilinx FPGA.

Thank you

Regards,

Bushra

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2 Replies
BushraH_91
Moderator
Moderator

Hello,

Thank you for contacting Cypress Technical Support, an Infineon Technology Company.  Xilinx boot process expects the Flash to be non-protected for Read access. It won’t issue an unprotect command, therefore the Flash should not be in read protection mode to be able to boot the Xilinx FPGA.

Thank you

Regards,

Bushra

View solution in original post

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rbork
New Contributor

Thank you. 

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