MSP430-Flash读写操作总结

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1、Four short words sum up what has lifted most successful individuals above the crowd: a little bit more.-author-dateMSP430-Flash读写操作总结MSP430X14X Flash 读写操作总结MSP430X14X Flash 读写操作总结开发平台：IAR Embedded Workbench、MSP430F149开发板作者：谭贝贝Flash简介Flash分为主存储区和信息存储区，主存储区有8个512byte的片段，信息存储区有两个128byte的片段。Flash默认为读取模式

2、。在对Flash进行编程或者擦除时不允许读写，如果需要CPU在这期间进行操作，可以把代码段放在RAM中进行。Flash操作注意事项在读写的过程中电压不能小于2.7V否则擦除和读写的结果将不可预测。Flash的可操作时钟频率为257KHZ-476KHZ。如果频率不符合要求，则结果不可预测。在擦除先需要关闭中断和看门狗，在擦除的过程中如果产生了中断，则会在重新使能中断后产生一个中断请求。Flash只能从1写为0，不能从从0写为1，所以需要擦除。可以被擦除的最小模块是片段，tAll Erase = tMass Erase = 5297/fFTG, tSeg Erase = 4819/fFTG。Fla

3、sh ERASEMSP430X14X的擦除模式可以从Flash或者RAM中进行。从Flash中擦除从Flash中擦除的过程中所有的定时都会被Flash控制，CPU被挂起。擦除完成后需要一个假写入CPU才能复位。从Flash擦除时有可能把后面CPU需要执行的代码擦除。如果发生这样的情况，在擦除后CPU的执行状况将不可预测。Flash中擦除流程图从RAM中擦除从RAM中擦除时CPU不会被挂起，可以继续执行代码。必须检测BUSY位以判断擦除是否结束，如果在擦除的过程中（即BUSY=1时）访问Flash，这是一个违规的访问，ACCVIFG会置位，而擦除的结果也将不可预测。RAM中擦除流程图Flash

4、WriteMSP430X14X有两种写入模式，分为段写入（byte/word write），和块写入（Block Write），块写入要快得多，但是操作麻烦，在擦除的过程中不能有一个Flash word(low + high byte)，则会发生损坏。CPU不能在BUSY=1时访问Flash，否则ACCFIG将置位写入将不可预测。1. Byte/Word writeByte/Word 写入可以从Flash或者RAM初始化，当从Flash中初始化时，所有的定时都会被Flash控制，CPU被挂起。写完后CPU将继续执行后面的代码。当从RAM中初始化时，BUSY必须在CPU访问Flash前置0.否则

5、ACCFIG将被置位，写入的结果将不可预测。在Byte/Word 写模式下写入总时间不能超过4ms,如果超过了，当再想这块任何地址写入数据时必须先擦除。Byte/Word 写入流程图从RAM中执行Byte/Word 写入块写入块写入时没一小块不能超过t_cpt=4ms,块写入只能从RAM中进行，在块写入的过程中WAIT位要置0，当想Flash中写入数据时，需要先检查WAIT位是否为1.当前块写完后BLKWRT要清0.流程图在擦除或者写入的过程中访问Flash，见下表Flash的寄存器FCTL1，选择擦除和写入模式的寄存器FRKEY/FWKEY 高八位为密码读的密码为96h，写的密码为A5h。B

6、LKWRT块写入模式选择位，可以自动被EMEX置位WRT字写入模式选择位，可任意自动被EMEX置位MERASE和ERASE，擦除模式选择位FCTL2时钟选择寄存器FWKEYx密码位FSSELx时钟选择位FNx分频比 分频值等于FN+1两个例子#include #include BoardConfig.hvoid Write_A(uchar value);void Copy_A2B(void);void main( void )/ Stop watchdog timer to prevent time out resetWDTCTL = WDTPW + WDTHOLD;BoardConfig(0

7、xb8);FCTL2 = FWKEY + FSSEL0 + FN0; /Select sourceuchar value = 0;for(;)Write_A(value+); /Write data to segment ACopy_A2B(); /Copy data from segment A to segment B_NOP();void Write_A(uchar value)uchar i;uchar *Flash_ptr;Flash_ptr = (uchar *)0x1080;FCTL1 = FWKEY + ERASE; /Set ERASE modeFCTL3 = FWKEY;

8、/Clear LOCK*Flash_ptr = 0; /Dummy writeFCTL1 = FWKEY + WRT;for(i = 0;i 128;i+)*Flash_ptr+ = value; /Write valueFCTL1 = FWKEY; /Clear WRTFCTL3 = FWKEY + LOCK; /Set LOCK/Copy data from B to Avoid Copy_A2B(void)uchar *Flash_ptrA;uchar *Flash_ptrB;uint i;Flash_ptrA = (uchar *)0X1080;Flash_ptrB = (uchar

9、*)0x1000;FCTL1 = FWKEY + ERASE;FCTL3 = FWKEY;*Flash_ptrB = 0;FCTL1 = FWKEY + WRT;for(i = 0;i 128;i+)*Flash_ptrB+ = *Flash_ptrA+;FCTL1 = FWKEY;FCTL3 = FWKEY + LOCK;再来个块写入的（TI例程）/*/ MSP430F14x Demo - Flash In-System Programming, BlockWrite/ Description: This program first copies the FlashWrite routine

10、 to RAM, then/ erases flash seg A, then it increments all values in seg A using the 64/ byte block write mode./ Assumed default MCLK = DCO 800 kHz./ Minimum RAM requirement = 512 bytes/ * Set Breakpoint on NOP in the Mainloop to avoid Stressing Flash */ MSP430F149/ -/ /| XIN|-/ | | |/ -|RST XOUT|-/

11、| |/ H. Grewal / L. Westlund/ Texas Instruments Inc./ Jun 2006/ Built with IAR Embedded Workbench Version: 3.30A/*#include / Global variableschar value = 0; / 8-bit value to write to segment Achar* Flash_ptr; / Flash pointerchar* RAM_ptr; / RAM pointerchar* END_ptr; / End of FlashWrite routine/ Func

12、tion prototypesvoid FlashWrite();void CopyRoutine();void End_of_FlashWrite();void main(void)WDTCTL = WDTPW + WDTHOLD; / Stop watchdog timer_DINT(); / Diable InterruptsCopyRoutine(); / Copy FlashWrite routine to RAM_EINT(); / Enable Interruptswhile(1) / Repeat foreverFlash_ptr = (char *) 0x1000; / In

13、itialize Flash pointerFCTL2 = FWKEY + FSSEL1 + FN0; / MCLK/2 for Flash Timing GeneratorFCTL1 = FWKEY + ERASE; / Set Erase bitFCTL3 = FWKEY; / Clear Lock bit*Flash_ptr = 0; / Dummy write to erase Flash segmentwhile(!(FCTL3 & WAIT); / WAIT until Flash is readyasm(CALL #300h); / Execute FlashWrite from

14、 RAM/ Inline Assemblyvalue+; / Increment value_NOP(); / SET BREAKPOINT HEREvoid CopyRoutine()Flash_ptr = (char*)FlashWrite; / Set pointer to FlashWrite routineRAM_ptr = (char*)0x0300; / Set pointer to RAMEND_ptr = (char*)End_of_FlashWrite; / Set pointer to End_of_FlashWritewhile(END_ptr != Flash_ptr

15、) / Check for end of FlashWrite*RAM_ptr = *Flash_ptr; / Copy word to RAMFlash_ptr+; / Increment Flash pointerRAM_ptr+; / Increment RAM pointervoid FlashWrite()volatile int i; / Use as write counterFlash_ptr = (char*)0x1000; / Initialize Flash pointerwhile(FCTL3 & BUSY); / Check Flash BUSY bitFCTL1 =

16、 FWKEY + BLKWRT + WRT; / Enable block-write operationfor(i = 0; i 64; i+)*Flash_ptr = value; / Write value to flashFlash_ptr+; / Double-increment Flash pointerwhile(!(FCTL3 & WAIT); / WAIT until Flash is readyFCTL1 = FWKEY; / Clear BLKWRT & WRT bitswhile(FCTL3 & BUSY); / Check Flash BUSY bitFCTL3 = FWKEY + LOCK; / Reset LOCK bitreturn; / Exits routinevoid End_of_FlashWrite() / Marks end of FlashWrite-