Port fatfs to external SPI FLASH on 52832？

[Lion]

Hi All,

We have a product that requires the use of the file system Fatfs, which is plugged into the external SPI FLASH.
Therefore, the hardware platform used is: n52832 + W25x10 (NOR FLASH)
The software uses SDK16.0, the path from the SDK .. \ examples \ peripheral \ fatfs uses the SD card, I want to realize the function of loading external FLASH to load Fatfs on the basis of this project?

I checked the example code of fatfs and found that the path: .. \ components \ libraries \ block_dev supports multiple media, but unfortunately there is no NOR FLASH.
How to load fatfs in NOR FLASH?

Thanks,

[Nguyen Hoan Hoang]

There is is a old French saying for "T'en a du pain sur la planche".  Which means you got work to do.  First of, Flash is not Fat formatted so you got to format it yourself. Second Flash erasable block varies from 4KB to 64KB.  So before a write can be made.  You need to erase the whole block. You got to manually manage that too. You are going to have fun with it because each sector size is 512 bytes.  So each time you write a sector, you copy a full block from flash to Ram. Write your sector to ram block at the right offset. Erase the flash block. Write the block from ram back to flash. I would recommend you use MMC instead. It's equivalent to SDCard but in form if chip. 

[Lion]

Thank you for your reply, this is really a difficult task.
FLASH capacity is 1Mbytes, sector unit is 4kbytes, block size is 64kbytes / 32kbytes, page size is 256bytes.
Write support page, erase support sector and block.

So, I have many questions, please support:
1. How to format flash to Fat?
Is this reasonable?
ff_result = f_mkfs ("0:", FM_FAT, 0, gFsWork, 4096);
2. I understand the operation of the flash block, read it first, then erase it, and write it again.
The block size is 64k / 32k, and the total memory size of n52832 is only 64k. This problem is too difficult. So I can choose to erase by sector, which only takes up 4k of memory.
I found result = MMC_disk_write (buff, sector, count); and result = MMC_disk_read (buff, sector, count) in the driver file of fatfs.
Flashes are operated by the sector, so I only need to erase the sector before disk_write?

Sector operations do bring speed limitations.

Thanks

[Nguyen Hoan Hoang]

Not sure what will to happen when you set a sector of 4KB.  A disk sector is 512 bytes and cluster can be 4KB but sector of 4KB ??? Don't know.  Let me know the results.

[Lion]

This is the FLASH DS that I used.
The size of the sector marked above is 4k.

XTX_SPI_NOR_XT25F08B_Rev 1.5.pdf

[Nguyen Hoan Hoang]

I didn't mean the flash.  I meant the Fat Filesystem specs.