Introduction
the POSIX functions fwrite(), fread() and fsetpos(). Another API with parallel argument
placement and meaningful return error codes is provided as an alternate, with functions like
FSFile_Wr(), FSFile_Rd() and FSFile_PosSet().
Scalable: The memory footprint of μC/FS can be adjusted at compile-time based on the
features you need and the desired level of run-time argument checking. For applications
with limited RAM, features such as cache and read/write buffering can be disabled; for
applications with sufficient RAM, these features can be enabled in order to gain better
performance.
Portable: μC/FS was designed for resource-constrained embedded applications. Although
μC/FS can work on 8- and 16-bit processors, it will work best with 32- or 64-bit CPUs.
RTOS: μC/FS does not assume the presence of a RTOS kernel. However, if you are using a
RTOS, a simple port layer is required (consisting of a few semaphores), in order to prevent
simultaneous access to core structures from different tasks. If you are not using a RTOS, this
port layer may consist of empty functions.
1-3 TYPICAL USAGES
Applications have sundry reasons for non-volatile storage. A subset require (or benefit from)
organizing data into named files within a directory hierarchy on a volume—basically, from
having a file system. Perhaps the most obvious expose the structure of information to the
user, like products that store images, video or music that are transferred to or from a PC. A
web interface poses a similar opportunity, since the URLs of pages and images fetched by
the remote browser would resolve neatly to locations on a volume.
Another typical use is data logging. A primary purpose of a device may be to collect data
from its environment for later retrieval. If the information must persist across device reset
events or will exceed the capacity of its RAM, some non-volatile memory is necessary. The
benefit of a file system is the ability to organize that information logically, with a fitting
directory structure, through a familiar API.
A file system can also store programs. In a simple embedded CPU, the program is stored at
a fixed location in a non-volatile memory (usually flash). If an application must support
firmware updates, a file system may be a more convenient place, since the software handles
the details of storing the program. The boot-loader, of course, would need to be able to
17
相关PDF资料
AD-UCOS3-SPRD PRD LIC UCOS3 RTOS CORE CCES SGL
AD-UCUSBD-SPRD PRD LIC UCUSB DEV CORE CCES SGL
AD637-EVALZ BOARD EVALUATION FOR AD637
AD736-EVALZ BOARD EVALUATION FOR AD736
AD737-EVALZ BOARD EVALUATION FOR AD737
AD8007AKS-EBZ BOARD EVAL FOR AD8007AKS
AD8018ARU-EVAL BOARD EVAL FOR AD8018
AD8034ART-EBZ BOARD EVAL FOR AD8034ART
相关代理商/技术参数
ADuC-H7020 功能描述:开发板和工具包 - ARM HDR BRD FOR ADUC7020 ARM7 RoHS:否 制造商:Arduino 产品:Development Boards 工具用于评估:ATSAM3X8EA-AU 核心:ARM Cortex M3 接口类型:DAC, ICSP, JTAG, UART, USB 工作电源电压:3.3 V
ADuC-IO7020 功能描述:开发板和工具包 - ARM DEV BRD FOR ADUC7020 ARM7 RoHS:否 制造商:Arduino 产品:Development Boards 工具用于评估:ATSAM3X8EA-AU 核心:ARM Cortex M3 接口类型:DAC, ICSP, JTAG, UART, USB 工作电源电压:3.3 V
ADUCM3027BCBZ-R7 功能描述:LOWPWR CORTEXM3W/128KKEMBEDDED F 制造商:analog devices inc. 系列:* 零件状态:在售 标准包装:1,500
ADUCM3027BCBZ-RL 功能描述:LOWPWR CORTEXM3W/128KKEMBEDDED F 制造商:analog devices inc. 系列:* 零件状态:在售 标准包装:5,000
ADUCM3027BCPZ 功能描述:IC MCU 32BIT 128KB FLASH 64LFCSP 制造商:analog devices inc. 系列:ADuCM 包装:托盘 零件状态:在售 核心处理器:ARM? Cortex?-M3 核心尺寸:32-位 速度:26MHz 连接性:I2C,SPI,UART/USART 外设:DMA,POR,PWM,WDT I/O 数:44 程序存储容量:128KB(128K x 8) 程序存储器类型:闪存 EEPROM 容量:- RAM 容量:96K x 8 电压 - 电源(Vcc/Vdd):1.74 V ~ 3.6 V 数据转换器:A/D 8x12b 振荡器类型:内部 工作温度:-40°C ~ 85°C(TA) 封装/外壳:64-WFQFN 裸露焊盘 供应商器件封装:64-LFCSP(9x9) 标准包装:1
ADUCM3027BCPZ-R7 功能描述:IC MCU 32BIT 128KB FLASH 64LFCSP 制造商:analog devices inc. 系列:ADuCM 包装:剪切带(CT) 零件状态:在售 核心处理器:ARM? Cortex?-M3 核心尺寸:32-位 速度:26MHz 连接性:I2C,SPI,UART/USART 外设:DMA,POR,PWM,WDT I/O 数:44 程序存储容量:128KB(128K x 8) 程序存储器类型:闪存 EEPROM 容量:- RAM 容量:96K x 8 电压 - 电源(Vcc/Vdd):1.74 V ~ 3.6 V 数据转换器:A/D 8x12b 振荡器类型:内部 工作温度:-40°C ~ 85°C(TA) 封装/外壳:64-WFQFN 裸露焊盘 供应商器件封装:64-LFCSP(9x9) 标准包装:1
ADUCM3027BCPZ-RL 功能描述:IC MCU 32BIT 128KB FLASH 64LFCSP 制造商:analog devices inc. 系列:ADuCM 包装:带卷(TR) 零件状态:在售 核心处理器:ARM? Cortex?-M3 核心尺寸:32-位 速度:26MHz 连接性:I2C,SPI,UART/USART 外设:DMA,POR,PWM,WDT I/O 数:44 程序存储容量:128KB(128K x 8) 程序存储器类型:闪存 EEPROM 容量:- RAM 容量:96K x 8 电压 - 电源(Vcc/Vdd):1.74 V ~ 3.6 V 数据转换器:A/D 8x12b 振荡器类型:内部 工作温度:-40°C ~ 85°C(TA) 封装/外壳:64-WFQFN 裸露焊盘 供应商器件封装:64-LFCSP(9x9) 标准包装:2,500
ADUCM3029BCBZ-R7 功能描述:LOWPWR CORTEX M3W/256KEMBEDDED F 制造商:analog devices inc. 系列:* 零件状态:在售 标准包装:1,500