Cyclone® V Hard Processor System Technical Reference Manual

ID 683126
Date 8/28/2023
Public
Document Table of Contents

16.5.6.3. XIP Mode at Power on Reset

Some flash devices can be XIP-enabled as a nonvolatile configuration setting, allowing the flash device to enter XIP mode at power-on reset (POR) without software intervention. Software cannot discover the XIP state at POR through flash status register reads because an XIP-enabled flash device can only be accessed through the XIP read operation. If you know the device may enter XIP mode at POR, have your initial boot software configure the modebit register and set the enterxipimm bit of the cfg register to 1.

If you do not know in advance whether or not the device may enter XIP mode at POR, have your initial boot software issue an XIP mode exit command through the flashcmd register, then follow the steps in the “Entering XIP Mode” section. Software must be aware of the mode bit requirements of the device, because XIP mode entry and exit varies by device.