[threadx] FileX Clarification for correct configuration on SPI Flash

[Davide Dal Frà <d.dalfra@xxxxxxxx>]

Hello Folks

 

I’m integrating FileX on a system that uses MX25L6433F which is a 64Mbit, SPI Flash where the minimum erasable block is 4K while the minimum programming page is 256byte.
The driver I use to write and read from/to the flash is something we’re successfully using since 5years, so the integration with LX driver has been done quite easy.

I would need some clarification on what really needs to be used as init parameters for the fx_media_format. More specifically if any of the following parameters need to respect some ratio or some physical configuration of the external flash (or are they just logical?)

/*    number_of_fats                        Number of FAT tables          */
I assume this should be 1, found in all examples both in ST and Renesas folders.

/*    directory_entries                     Number of directory entries   */

32. I think this is more related to the FAT structure, so nothing care about flash physical characteristics. Right?

 

/*    hidden_sectors                        Number of hidden sectors      */

0, Same as before.

 

/*    total_sectors                         Total number of sectors       */
Shall this be related to the flash physical configuration?
I.e., if my flash is 64 MBIT = 8192KB, shall this respect the number of 4K sector available ? (8192KB/4KB = 2048 )

Or shall be based on the minimum page write size capability (256 byte) ?

 

/*    bytes_per_sector                      Number of bytes per sector    */
Same consideration as before. Is this related to physical characteristic ?( so I assume 4096byte in case we consider the minimum erasable capability of the flash)
Or is something logical that does not care about physical flash feature?

 

/*    sectors_per_cluster                   Number of sectors per cluster */

1, assume this is just logical

 

/*    heads                                 Number of heads               */
1, assume this is just logical

 

/*    sectors_per_track                     Number of sectors per track   */

1, assume this is just logical

 

 

Furthermore (promise, this is the last question): The define LX_NOR_SECTOR_SIZE , shall respect the minimum erasable sector of the flash ? I see examples that takes values starting from 256 to 512 byte.

/* Define the logical sector size for NOR flash. The sector size is in units of 32-bit words.

   This sector size should match the sector size used in file system.  */

/*

#define LX_NOR_SECTOR_SIZE                          (512/sizeof(ULONG))

 

Thanks in advance to ll for the time spent for reading my email,

 

Regards

Davide