Hi,

I am trying to access in read and write my EPCQL-1024. I have the Altera Serial Flash Controller I configured in QUAD mode connected from its avl_csr and avl_mem to the NIOSII.

1. I have tried to access in read and write the EPCQL registers (STATUS, Device ID) and the controller registers FLASH_ISR, or FLASH_IMR, protect sectors also and it have been successful.
2. Here lies my problem: 

After WRITE operations (erase sector or write bytes), the device does not respond to any instruction except the READ STATUS REGISTER, although the read status register value indicates that there is no erase or write cycle in progress (the WIP bit is 0 so the write operation is completed). I need to power off the chip then power on and reconfigure my FPGA to regain control over the memory and get values back from my EPCQL ,the data read back after power down being as expected!

I’m wondering if the logic inside flash memory devices requires a power down after each WRITE operation.

Any help or points in a direction would be much appreciated. Thank you in advance.