Introduction to LEVELX

This message will disappear after all relevant tasks have been resolved.

Semantic MediaWiki

There are 1 incomplete or pending task to finish installation of Semantic MediaWiki. An administrator or user with sufficient rights can complete it. This should be done before adding new data to avoid inconsistencies.

1. Introduction

LevelX is a library offering the wear leveling and bad block management features for flash memories. LevelX is not intended to provide FileSytem APIs but only, low-level API to read, write, erase sectors in flash memories. Combined with FileX, it allows seamlessly using NAND and NOR flash memories as media storage devices.

LevelX is designed in a modular way, that facilitates the support of any flash memory. In fact, LevelX requires a low-level driver interacting with the Flash memory to support the basic raw API, read blocks, write blocks, Erase blocks and check errors. These raw APIs are then logically combined to offer a more user-friendly high-level APIs. The main features offered by LevelX are:

Data Read/Write
Flash erase
Flash defragmentation
Wear leveling
Error checks

Further details are available in the LevelX official documentation

2. STM32 Integration

LevelX is targeting, mainly, the following types of memories:

NOR memories (SPI/QSPI/OSPI), making use of wear-leveling and bad block management features.
NAND memories, also, making use of wear-leveling and bad block management features.
SRAM memories: covering any MCU internal volatile memory (DTCM, AXISRAM…). This is specifically useful for fast prototyping and testing.

2.1. Known Limitations

No known limitations so far. More details are in the official LevelX official documentation

3. How To Use

LevelX shall be used alongside with FileX. Please refer to FileX page "How To Use" section for more details about how to use LevelX

LevelX requires low-level interfaces to support the above-mentioned HW devices:

lx_stm32_xxx_driver_template.c/stm32_lx_xxx_driver_template.h An empty interface, provided as skeleton that can be modified by the user to support a custom flash memory.

lx_stm32_*_driver.c: LevelX driver patterns that are ready to use by the application. They are delivered as part of the LevelX source code. The drivers may differ between STM32 series depending on the supported features.

lx_stm32_*_driver_template.h: A template configuration header file to tune the corresponding driver for specific STM32 MCU/Board. This file should be copied in the application source tree and renamed to “lx_stm32_*_driver.h” then customized according to the driver needs.

Configuration flags can be defined by user in the “xxx_driver_template.h” file. Below LevelX driver OCTO-SPI header template file as an example:

#ifndef LX_STM32_QSPI_DRIVER_H
#define LX_STM32_QSPI_DRIVER_H

#ifdef __cplusplus
extern "C" {
#endif

/* Includes ------------------------------------------------------------------*/
#include "lx_api.h"
#include "stm32h747i_discovery_qspi.h"

/* Exported types ------------------------------------------------------------*/
/* Exported constants --------------------------------------------------------*/
/* the QuadSPI instance ,default value set to 0 */
#define QSPI_INSTANCE   0
#define DEFAULT_BLOCK_SIZE (4 * 1024)

/* when set to 1, the QSPI init is done by the driver, otherwise it is up to the application to intialize it */
#define LX_DRIVER_CALLS_QSPI_INIT 1

#if (LX_DRIVER_CALLS_QSPI_INIT == 1)

/* allow the driver to fully erase the QuadSPI chip. This should be used carefully.
 * the call is blocking and takes a while. by default it is set to 0.
 * When creating a fresh file system on the NOR Flash this flag should be enabled.
 */
#define LX_DRIVER_ERASES_QSPI_AFTER_INIT  1
#endif

/* Exported macro ------------------------------------------------------------*/
/* Exported functions prototypes ---------------------------------------------*/
UINT  lx_stm32_qspi_initialize(LX_NOR_FLASH *nor_flash);

/* Private defines -----------------------------------------------------------*/

#ifdef __cplusplus
}
#endif
#endif /* LX_STM32_QSPI_DRIVER_H */

4. STM32 LevelX Applications

To be Updated.

STM32 Packages provide the following set of applications (supported applications list may differ between products and boards):

Application	Short Description
Fx_NAND_Write_Read_File	It demonstrates how to create a Fat File system on the NAND flash using FileX alongside LevelX. The application is designed to execute file operations on the Micron MT29F2G16ABAEAWP NAND flash device, the code provides all required software code for properly managing it. [readme]