 RL-ARM User's Guide | |
| Home Products Events Support | |
Technical Support
On-Line Manuals
RL-ARM User's Guide
RL-RTX 
RL-FlashFS Flash Memory Management 
Memory Organization File Allocation Information File Data Blocks Technical Data Configuring Flash File System Configuration Flash Device Sector Memory Map FS_FlashDev.h Converting FlashDev.c Program and Erase Code FS_FlashPrg.c Converting FlashPrg.c SPI Flash Device FS_SPI_FlashDev.h Programming Code FS_SPI_FlashPrg.c RAM Device Memory Card Device MCI Interface SPI Interface File Time Support System Configuration Library Files Using Flash File System Using Flash Devices Using Dedicated Flash Devices Using One Large Flash Device Using Internal Flash Devices Using RAM Devices RAM Configuration Example Using Memory Card Devices Hot Insertion Root Directory Limitation Debugging Function Overview File I/O Routines File Maintenance Routines File Time Support Routines Low-Level Routines SPI Interface Routines System Functions RL-TCPnet RL-CAN Example Programs Library Reference AppendixMemory Organization
The memory organization of a Flash Device is divided into flash sectors. The Flash Sector is typically a 64 KB memory page and is written cell after cell. The memory cell size depends on the device architecture and is 8-bit wide (byte), 16-bit wide (half word) or 32-bit wide (word). When you want to erase the flash data, you need to erase the whole flash sector at once. Flash Sectors are named Blocks in RL-FlashFS.
Each block contains its own allocation information on top of memory. The filenames and file content are on lower memory. If the file is bigger and does not fit into a single block, it is stored in several blocks. Several smaller files are stored into a single Block. The file allocation information is written to the File allocation table located at the top of the Flash Block.
When the content of the file is modified, the old file content is invalidated and the new memory block is allocated. The Flash Block is erased when all the data stored in the Flash Block is invalidated.
| Contact Site Map Press Privacy | Copyright © 2010 Keil™, An ARM® Company. All rights reserved. |
