MX25L12845E参考代码

/* * COPYRIGHT (c) 2010 MACRONIX INTERNATIONAL CO., LTD * SPI Flash Low Level Driver (LLD) Sample Codes * * This README file introduces low level driver of MX25-series. * * Filename : README.txt * Issued Date: Feb. 05, 2010 * * Any questions or suggestions, please send mails to: * * flash_model@mxic.com.tw */ * Notice: All source files are saved as UNIX format. This README file describes the functions of MXIC MX25-series low level driver (LLD) sample codes. It consists of several sections as follows: 1. Overview 2. File structure 3. Functions 4. Porting 5. Return messages 1. Overview --------------------------------- The MX25-series LLD sample codes are useful for programmers to development flash drivers or software applications of MX25-series SPI flash products. The included source codes are ANSI C compliant. Any ANSI C compliant complier can be compiled with these codes. The MX25-series LLD sample codes have been verified under hardware and software co-simulation platform with standard 8051 IP core. All the contents of LLD sample code are for reference only. It might contain some unknown problems. MACRONIX will not be liable for any claims or damages due to the use of LLD sample codes. 2. File Structure --------------------------------- 2.1 File content The following files will be available after extracting the zipped file (or other compression format): MX25XXXX\ |- README.txt |- MX25_CMD.c |- MX25_CMD.h |- MX25_DEF.h |- MX25_APP.c These files are key elements of LLD and function in different ways. Here are the details of these files: MX25_CMD.c (.h): Flash command sequences of flash devices. The number of commands depend on the type of devices. All the commands are programmed according to the datasheet of flash products. MX25_DEF.h: Definitions of flash devices and program parameters. MX25_APP.c: Sample codes of applications for references. This file is not a major one of LLD. The naming rule of MX25-series LLD sample codes is as follows: MX25_XXX.x: --- - | |--> c or h. Source codes or header file. | |-----> CMD, DEF or APP. File names represent for different functions. 2.2 File dependency MX25_APP.c | |- <stdlib.h> (*Note1) |- MX25_CMD.h <-> MX25_CMD.c | |- <8051.h> (*Note2) |- MX25_DEF.h *Note1: This header file is for MX25_APP.c to generate random data. *Note2: This header file is optional. It needs to be included if the system uses 8051 micro-controller and connected flash device via GPIO port. 3. Function descriptions -------------------------------- The MX25-series SPI flash contains special I/O transfer modes besides traditional SPI mode. These modes are QPI and PARALLEL mode (*Note3). LLD source codes are different between these modes even if the same flash command. Types of function of LLD are introduced at section 3.1 and command mapping at section 3.2. 3.1 Types of Function: There are three types of function for LLD as follows: a. Basic function: Include CS_Low(), CS_High(), InsertDummyCycle(), SendByte() and GetByte(). Basic functions are highly hardware dependent. You usually need to modify the functions for different hardwares applications. Please see section 4 for details. b. Command function: Command function is the major part of LLD. It is used to describe the command sequences of flash commands defined in the datasheet. Normally, the sequences from LLD and datasheet are fully matched. However, please follow the datasheet if any discrepancies. Naming rules of command function are as follows: ReturnMsg CMD_XXX(...); Where XXX is a command name like RDID, READ, and so on. ReturnMsg report the execution result of the command. Section 5 describes more about the return messages. c. Utility function: Those commands which are neither basic nor command functions belong to utility functions. Utility function provides some unique functionality to make LLD work smoothly. 3.2 Command mapping As mentioned at section 3.1.b, the command functions are implementation of command sequences defined in the datasheet. In this section, the mapping of command sequence and command function is introduced. Here takes the RDID command as a example. a. RDID command sequence: CS# goes low-> send RDID instruction code-> 24-bits ID data out on SO-> to end RDID operation can drive CS# to high at any time during data out. b. RDID command function: ReturnMsg CMD_RDID( uint32 *Identification ) { uint32 temp; uint8 gDataBuffer[3]; // CS# goes low CS_Low(); // Send RDID instruction code SendByte( FLASH_CMD_RDID, SIO ); // 24-bits ID data out on SO gDataBuffer[0] = GetByte( SIO ); gDataBuffer[1] = GetByte( SIO ); gDataBuffer[2] = GetByte( SIO ); // CS# to high to end RDID operation CS_High(); // Store ID data and return temp = gDataBuffer[0]; temp = (temp << 8) | gDataBuffer[1]; *Identification = (temp << 8) | gDataBuffer[2]; return FlashOperationSuccess; } In this example, the procedures of command sequence and command function are matched. The other sequences and functions are similar to this example. Feel free to verify the relationship between different commands. *Note3: SPI : Flash devices support Serial Peripheral Interface (SPI) mode only. QPI : Flash devices support both Serial Peripheral Interface (SPI) mode and Quad Peripheral Interface (QPI) mode. SPAR: Flash devices support both Serial Peripheral Interface (SPI) mode and serial flash's parallel (SPAR) mode. (This parallel mode is not equivalent to the one of MX29 parallel flash series.) 4. Porting -------------------------------- The MX25-series LLD sample codes are verified by 8051 IP core. And it uses 8051's GPIO ports to connect flash device. With different target hardware platforms, it is necessary to modify the LLD source codes. In this section, porting notices are introduced. And it is divided into data types, definitions of options and function modification for your references. 4.1 Data types For the ability of port LLD to different target system, the length of data type can be modified in the MX25_DEF.h header file. Please verify these data types before applying. Basic data type: typedef unsigned long uint32; /* 32 bit wide */ typedef unsigned int uint16; /* 16 bit wide */ typedef unsigned char uint8; /* 8 bit wide */ typedef unsigned char BOOL; /* 1 bit wide */ 4.2 Definition options There are several definition options available based on the target system. System option: #define MCU8051 /* Use 8051 as micro-controller */ #define GPIO_SPI /* Use GPIO port to connect flash */ #define MX25XXX /* Flash part name */ #define NON_SYNCHRONOUS_IO /* MCU is not busy waiting */ MCU option: #define CLK_PERIOD /* MCU clock speed */ #define Min_Cycle_Per_Inst /* Cycle count per instruction */ #define One_Loop_Inst /* Instruction count per loop */ 4.3 Function modifications As mentioned at section 3.1, basic functions are highly dependent on the hardwares. And some utility functions work the same. These functions should be modified based on different hardware architectures. They are displayed as follows: void CS_Low(); void CS_High(); void InsertDummyCycle( uint8 dummy_cycle); void SendByte( uint8 byte_value, uint8 transfer_type ); uint8 GetByte( uint8 transfe