The SoC Hardware Library (HWLIB) configures and controls the SoC Quad Serial Peripheral Interface (SPI) Controllers. The QSPI HWLIB source can be found in the /ip/altera/hps/altera_hps/hwlib/include/alt_qspi.h file. The alt_qspi.h file contains the following comment:
* 1. Qspi Direct Access Mode is not working!
*
* This is because the qspi flash memory installed on our DevKit board, Micro
* part N25Q00xx, 8 Gb, is not completely compatible with our embedded Synopsis
* QSPI controller IP. Therefore there is no viable direct access code offered
* in the lib. All the memory rea/write functionality is offered with indirect
* access only.
*
* Should you install a different flash memory part in your custom board, and
* wondering wether direct access mode works, please contact with us.
******************************************************************************/
This statement simply warns customers that for multi die implementation, the controller needs to read extra status flag commands that are not supported at the moment.
This problem is scheduled to be fixed in a future version of the Altera SoC Embedded Design Suite.