Problems using the NOR flash for storage

Official Hardware Mega GIGA R1 WiFi
1

I have some routines that work with Winbond flash chips, as used on Adafruit's Express microcontroller boards, and as far as I can see the flash on the GIGA is compatible with these. However, I can't seem to get my routines to work on the GIGA.

I'm using it in single-bit mode, with the pin assignments in pins_arduino.h:

#define QSPI_SO0        PD_11
#define QSPI_SO1        PD_12
#define QSPI_SO2        PE_2
#define QSPI_SO3        PF_6
#define QSPI_SCK        PF_10
#define QSPI_CS         PG_6

However, when I issue a READID command (0x90) to read the device ID, I get 0xFF rather then the correct value 0x17. Any suggestions?

2

I think I've worked out what the problem is. It seems that these pins are blocked from being accessible to a user's program, such as via Arduino commands like pinMode() and digitalWrite().

Would it be possible to make them accessible?

4

I've realised that user access to the QSPI Flash is a bad idea, because it is required to store the Wi-Fi firmware.

5

It's worth mentioning that there are lots of good ways to partition the QSPI flash to safely allow for other uses without affecting the WiFi firmware. The GIGA platform comes with Examples for displaying the current flash partitioning and another to repartition it if necessary. Another Example allows restoring the WiFi firmware.