TI中文支持网28377s在仿真时，通过On-Chip Flash，将Z1-BOOTCTRL改为0xFFFFFFFE，点击Program OTPBOOTCTRL，写入成功。想要再次修改Z1-BOOTCTRL为0xFFFFFF5A时却发现不能成功。
已知OTP flash中每一位从1写为0只能写一次，我将Z1-BOOTCTRL中的最后一位写0，改为0xFFFFFFFE后，想要再将其他位由1写为0却无法成功，请问这是什么原因？
Green Deng：OTP只能被编程一次，并且不能被擦除。如果要二次编写的话需要用到flash API函数，并且如你所说，它的每个位只能由“1”改为“0”不可逆。
28377s在仿真时，通过On-Chip Flash，将Z1-BOOTCTRL改为0xFFFFFFFE，点击Program OTPBOOTCTRL，写入成功。想要再次修改Z1-BOOTCTRL为0xFFFFFF5A时却发现不能成功。
已知OTP flash中每一位从1写为0只能写一次，我将Z1-BOOTCTRL中的最后一位写0，改为0xFFFFFFFE后，想要再将其他位由1写为0却无法成功，请问这是什么原因？
user5188513：
回复 Green Deng:
你好，按照你说的用flash API函数。我用ti中的例程在Z1-BOOTCTRL寄存器(0x7801E)写入0xFFFFFF5A，仍然是不能成功。
以下是程序：
Flash_Addr = 0x0007801E,sbuf = 0xFFFFFF5A,length = 2.
void Flash_program(USIGN32 Flash_Addr,USIGN16 *sbuf,USIGN16 length)
{
USIGN32 *Buffer32 = (USIGN32 *)sbuf;
USIGN32 u32Index = 0;
Fapi_StatusType oReturnCheck;
volatile Fapi_FlashStatusType oFlashStatus;
Fapi_FlashStatusWordType oFlashStatusWord;
if(Flash_Addr < 0xC0000){
PUMPREQUEST = 0x5A5A0002;// Give pump ownership to FMC0
// This function is required to initialize the Flash API based on System
// frequency before any other Flash API operation can be performed
// Note that the FMC0 register base address is passed as the parameter
oReturnCheck = Fapi_initializeAPI(F021_CPU0_W0_BASE_ADDRESS, 150);
if(oReturnCheck != Fapi_Status_Success)
{
SciaRegs.SCITXBUF.bit.TXDT = 0xA0;//失败时发送0xA0
while(SciaRegs.SCICTL2.bit.TXEMPTY == 0){}
for(;;);
}
// Fapi_setActiveFlashBank function sets the Flash bank0 and FMC0 for
// further Flash operations to be performed on the bank0.
// Note that the parameter passed is Fapi_FlashBank0 since FMC0 register
// base address is passed to Fapi_initializeAPI()
oReturnCheck = Fapi_setActiveFlashBank(Fapi_FlashBank0);
if(oReturnCheck != Fapi_Status_Success)
{
SciaRegs.SCITXBUF.bit.TXDT = 0xA0;//失败时发送0xA0
while(SciaRegs.SCICTL2.bit.TXEMPTY == 0){}
for(;;);
}
// Disable ECC so that error is not generated when reading Flash contents
// without ECC
Flash0EccRegs.ECC_ENABLE.bit.ENABLE = 0x0;
u32Index = Flash_Addr;
oReturnCheck = Fapi_issueProgrammingCommand((uint32 *)u32Index,sbuf,
length,0,0,
Fapi_DataOnly);
while(Fapi_checkFsmForReady() == Fapi_Status_FsmBusy);
if(oReturnCheck != Fapi_Status_Success)
{
SciaRegs.SCITXBUF.bit.TXDT = 0xA0;//失败时发送0xA0
while(SciaRegs.SCICTL2.bit.TXEMPTY == 0){}
for(;;);
}
// Read FMSTAT register contents to know the status of FSM
// after program command for any debug
oFlashStatus = Fapi_getFsmStatus();
// Verify the values programmed. The Program step itself does a verify
// as it goes. This verify is a 2nd verification that can be done.
oReturnCheck = Fapi_doVerify((uint32 *)u32Index,length/2,Buffer32,
&oFlashStatusWord);
if(oReturnCheck != Fapi_Status_Success)
{
SciaRegs.SCITXBUF.bit.TXDT = 0xA0;//失败时发送0xA0
while(SciaRegs.SCICTL2.bit.TXEMPTY == 0){}
for(;;);
}
}
}
程序执行Fapi_issueProgrammingCommand时，返回Fapi_Status_Success，但其实目标位置并没有写入正确的0xFFFFFF5A，仍为0xFFFFFFFE.
在执行Fapi_doVerify时，返回Fapi_Error_Fail.
不知道你说的flash API函数是不是我调用的这个函数。麻烦再解答一下，感谢！
