I am evaluating the Keil File System Middleware. I have encountered a problem. Hopeful someone could give me a quick and clear hint.
It seems there are two types of file systems in the FS middle ware: Embedded FS and FAT FS.
Could someone tell me the differences between this two types.
I have noticed that NOR flash type be configured to use the Embedded FS type.
Could this Embedded FS be compatible with the USB Mass storage Class?(Treated as a plugged U Disk by the PC).
Could NOR Flash be configured to use the FAT FS? I have noticed the open source FAT FS doesn't distinguish the NOR Flash from other storage media.
Could a pure SPI Flash(i.e. Winbond W25Q32) be configured as the NOR Flash? The official Keil Pack includes a special NOR Flash(AT45DB642D) which supported both bus style NOR flash access method and a SPI style.
Thanks.
There exist AT45DB15(32,64) family of devices with small sectors (512bytes) that can be used with FAT-type file systems directly. As I said, I've modified Keil's RAM disk driver for the purpose and use it with AT45DB16 in several devices. You can do the same. The only modification is required in fs_config.h file. You should use Keil's original file, modify it and save with your project files so copmiler will use it when compiling fs_config.c instead of default one. And of course, you must write serial driver for sector read/write yourself...
Thank you, Dejan Durdenic.
I would not modify my hardware to justify the Keil's twisted middle ware design. My hardware uses a SPI Flash with 4K sector. I have returned to the open source FAT FS I adopted in my previous project. It works fine for me. So far I have not found any inconvenience.
So what is final verdict. Can we use NOR flash with Keil FAT FS or with open source FATfs library?