currently I evaluate 2 types of flash which is connected to the 4SPI1 interface of the VF6xx:
1. Winbond W25Q32FV
2. Spansion S25FL128S
I have got 2 HW platforms: one is equiped with Winbond flash, the other one is equiped with Spansion flash.
For the evaluation I generate a blinking software in which the QuadSPI configuration parameters are almost identical except DDR mode (byte offset 54)
since the Winbond does not support DDR mode, in the LUT there is only a Fast Read Sequence, RM Chapter 188.8.131.52, page 1287.
For both types of flash the "quad enable" bit of each flash needs to be set to "1" so that the Boot ROM code of VF6xx can boot the app.-code from flash into OCRAM successfully.
Due to the data sheet of the Winbond W25Q32FV it needs explicit a command (0x38) to enter the QPI mode after powerup although the "quad enable" bit is set to "1",
otherwise it remains in "Standard/Dual SPI and Quad SPI" mode. Since the above mentioned command (0x38) for entering into QPI mode does not exist anywhere for the Boot ROM code,
so the Winbond W25Q32FV must remain in "Standard/Dual SPI and Quad SPI" mode after POR.
1. Question: Why does the "quad enable" bit of Windbond flash need to be set to "1" so that the Boot ROM code can boot successfully ?
2. Question: What kind of mode, "Standard/Dual/Quad SPI" mode or QPI mode does the Boot ROM code of VF6xx require ?
I would be very appreciated for any hints or answers, thank you in advance.
Winbond Data sheet: Publication Release Date: Sept 16, 2013 Rev. H