Part # Application Note Other Industrial M28W800CT M28W160CT M28W320CT M28W800CB M28W160CB M28W320CB AN1203 datasheet

Part Manufacturer: ST Microelectronics

ST Microelectronics

Part Description: Software drivers for M28W800C, M28W160C and M28W320C Flash memories


Part Details:

AN1203 APPLICATION NOTE Software Drivers for the M28W800C, M28W160C and M28W320C Flash Memories CONTENTS INTRODUCTION s INTRODUCTION This application note provides library source code in C for the s THE M28WxxxC M28W800CB, M28W800CT, M28W160CB, M28W160CT, PROGRAMMING MODEL M28W320CB and M28W320CT Flash Memories. There aretwo types of each Flash Memory, a Top Boot Block and a Bot- s WRITING C CODE FOR tom Boot Block, both types are covered in the C code. The set THE M28WxxxC of Flash Memories will be referred to as M28WxxxC throughout s C LIBRARY FUNCTIONS this document. PROVIDED Listings of the source code can be found at the end of this doc- s PORTING THE DRIVERS ument. The source code is also available in file form from the TO THE TARGET SYSTEM internet site http://www.st.com or from your STMicroelectronics s LIMITATIONS OF THE distributor. The c1203_16.c and c1203_16.h files contain librar- SOFTWARE ies for accessing the M28WxxxC Flash Memories. s CONCLUSION Also included in this application note is an overview of the pro- s c1203_16.h LISTING gramming model for the M28WxxxC. This will familiarize thereader with the operation of the memory devices and provide a s c1203_16.c LISTING basis for understanding and modifying the accompanyingsource code. The source code is written to be as platform independent aspossible and requires minimal changes by the user in order tocompile and run. The application note explains how the usershould modify the source code for their individual target hard-ware. All of the source code is backed up by comments explain-ing how it is used and why it has been written as it has. This application note does not replace the M28WxxxCdatasheet. It refers to the datasheet throughout and it is neces-sary to have a copy in order to follow some of the explanations. The software and accompanying documentation has been fullytested on a target platform. It is small in size and can be appliedto any target hardware. The M28WxxxC provides all the hardware and software func-tionality available on Intel s Advanced Boot Block Flash Mem-ories. Source code written for Intel s Advanced Boot BlockFlash Memories can easily be modified to use STMicroelec-tronics M28WxxxC memory instead. The M28WxxxC Flash Memory is compatible with the JEDECCommon Flash Interface (CFI). This interface allows softwareto identify the physical memory layout and command set of theFlash Memory. Software that is CFI compatible and includesthe correct programming algorithm will automatically be able to September 2001 1/31 AN1203 - APPLICATION NOTE identify and operate the memory. In this case the software drivers accompanying this application note willnot be required. Note that the software drivers provided with this application note are not CFI drivers andthat they are targeted solely at the M28WxxxC Flash Memory. THE M28WxxxC PROGRAMMING MODEL The M28WxxxC can be electrically erased and programmed through special coded command sequenceson most standard microprocessor buses. The device is broken down into different blocks of varying sizes.The Main Blocks are 32Kb x16 in size, whereas the Parameter Blocks are 4Kb x16 in size. Each block canbe protected and unprotected to prevent or allow Progam or Erase commands from affecting the memory,the protection state is volatile. The M28WxxxC is a smart voltage device. It differs from first generation devices which require a 12V sup-ply to program or erase. The M28WxxxC is therefore easier to use since the hardware does not need tocater for special bus signal levels. The voltages needed to erase the device are generated by chargepumps inside the device. Three power supply pins are used to give the optimal supply voltage conditions.In the simplest model all three voltage supply pins can be supplied with 2.7 to 3.6V. All operations areavailable in this mode. Alternatively the input/output driver section (supplied by VCCQ) can be supplieddown to 1.65V to interface to 1.8V Microcontrollers. The program/erase section can be supplied with 12Vto speed up programming in the factory; this mode is not to be used as a permanent solution. Included in the device is a Program/Erase Controller. With first generation Flash Memory devices the soft-ware had to manually program all of the words to 0000h before erasing to FFFFh using special program-ming sequences. The Program/Erase Controller in the M28WxxxC allows a simpler programming modelto be used, by taking care of all the necessary steps required to erase and program the memory. This hasled to improved reliability so that in excess of 100,000 program/erase cycles are guaranteed per block onthe device. Bus Operations and Commands Most of the functionality of the M28WxxxC is available via the two standard bus operations: read and write.Read operations retrieve data or status information from the device. Write operations are interpreted bythe device as commands, which modify the data stored or the behavior of the device. Only certain specialsequences of write operations are recognized as commands by the M28WxxxC. The various commandsrecognized by the M28WxxxC are listed in the Instructions Table of the datasheet; the main commandscan be grouped as follows: 1. Read 2. Read Electronic Signature 3. Erase 4. Program 5. Program/Erase Suspend


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Application Note Other Industrial M28W800CT M28W160CT M28W320CT M28W800CB M28W160CB M28W320CB AN1203.pdf Datasheet