Using NAND Flash with QSPI on SAMA5D22

Discussion around products based on ARM Cortex-A5 core.

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lrumanroe
Posts: 4
Joined: Mon Jan 20, 2020 8:18 pm

Using NAND Flash with QSPI on SAMA5D22

Thu May 14, 2020 10:17 pm

The hardware engineer on my project has decided to swap out the NOR Flash that I use for storage with an ISSI IS37SML01G1-LLI NAND flash. However, looking through the datasheet I found out that the addressing scheme require by the ISSI chip is a bit different from the QSPI used SAMA5D. The Program Load in the ISSI flash requires a 16-bit (4 dummy bits + 12-bit address) address. However the QSPI only has options for 24 and 32 bit addresses.

Does this mean that I will not be able to use QSPI with this flash, or is there a way to get the QSPI to sent out a 16-bit address?

Thank you.
blue_z
Location: USA
Posts: 2079
Joined: Thu Apr 19, 2007 10:15 pm

Re: Using NAND Flash with QSPI on SAMA5D22

Fri May 15, 2020 3:07 am

lrumanroe wrote: ... the NOR Flash that I use for storage ...
Of course you would use nonvolatile memory for "storage".
Or is that your oblique way of describing it as a "nonbootable device"?

lrumanroe wrote: Does this mean that I will not be able to use QSPI with this flash...
No, but if you are using Linux, then there's work to develop a Linux driver.
lrumanroe wrote: ...is there a way to get the QSPI to sent out a 16-bit address?
Yes, the fields of the instruction format can be kludged. Comments in the atmel-quadspi.c driver describe the workaround(s):

Code: Select all

	/*
	 * The controller allows 24 and 32-bit addressing while NAND-flash
	 * requires 16-bit long. Handling 8-bit long addresses is done using
	 * the option field. For the 16-bit addresses, the workaround depends
	 * of the number of requested dummy bits. If there are 8 or more dummy
	 * cycles, the address is shifted and sent with the first dummy byte.
	 * Otherwise opcode is disabled and the first byte of the address
	 * contains the command opcode (works only if the opcode and address
	 * use the same buswidth). The limitation is when the 16-bit address is
	 * used without enough dummy cycles and the opcode is using a different
	 * buswidth than the address.
	 */
However AFAIK there is no SPI protocol driver for that SPI NAND chip.

Regards
lrumanroe
Posts: 4
Joined: Mon Jan 20, 2020 8:18 pm

Re: Using NAND Flash with QSPI on SAMA5D22

Fri May 15, 2020 4:41 pm

That tells me what I need to know. Thank you.

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