MM32 备份域学习(兼容STM32)

内容提要

• 备份域工作原理
• 备份域特性
• 备份域的保护：侵入检测
• 备份域侵入检测

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备份域电源与主要内容

备份域特性

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侵入检测理解

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备份域侵入检测测试

void TamperEventTest()

{

    //设置时钟PWR和BKP

    RCC_APB1PeriphClockCmd(RCC_APB1Periph_BKP,ENABLE);

    RCC_APB1PeriphClockCmd(RCC_APB1Periph_PWR,ENABLE);

    PWR_BackupAccessCmd(ENABLE);  //使能访问备份域和RTC

    //侵入引脚时钟设置

    RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOA,ENABLE);

    //初始化备份域

    RCC_BackupResetCmd(ENABLE);

    RCC_BackupResetCmd(DISABLE);

    //设置备份域时钟

    RCC_LSEConfig(RCC_LSE_ON);    //Configures the External Low Speed oscillator (LSE).

    RCC_RTCCLKCmd(ENABLE);        //Enables or disables the RTC clock.

    RCC_RTCCLKConfig(RCC_RTCCLKSource_LSE); //Configures the RTC clock (RTCCLK).

    while(!(RCC->BDCR & 0x1<<1)); //External low-speed clock ready flag.

    BKP_ClearFlag();  //Set CTE bit to clear Tamper Pin Event flag

    //配置信号控制(PA1)侵入检测的信号(PC13)

    GPIO_InitTypeDef    GPIO_InitStructure;

    GPIO_InitStructure.GPIO_Pin = GPIO_Pin_0;

    GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF_PP;

    GPIO_Init(GPIOA, &GPIO_InitStructure);

    //write backup registers

    BKP_WriteBackupRegister(BKP_DR1, 0xA5A5);

    BKP_WriteBackupRegister(BKP_DR2, 0x8888);

    BKP_WriteBackupRegister(BKP_DR3, 0x6666);

    BKP_WriteBackupRegister(BKP_DR4, 0x9999);

    BKP_WriteBackupRegister(BKP_DR5, 0x9999);

    BKP_WriteBackupRegister(BKP_DR6, 0x9999);

    BKP_WriteBackupRegister(BKP_DR7, 0x9999);

    BKP_WriteBackupRegister(BKP_DR8, 0x9999);

    BKP_WriteBackupRegister(BKP_DR9, 0x9999);

    BKP_WriteBackupRegister(BKP_DR10, 0x9999);

    BKP->CR=0x01;

    GPIOA->ODR=1;//set PA[0]=1 >> set PC[13]

    while(1)

    {

        if((BKP->CSR &0x100)==0x100)//tef tamper event flag

            {

                //A write to the BKP->DRx register is performed while tef is set the value will not be stored

                BKP->DR1=0x6666;

                BKP->DR2=0x6666;

                delay(100);

                BKP->CSR=0x1;//clear tamper event flag;侵入检测，将使备份域复位

                break;

            }

    }

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实验注意事项

• 设置了两个GPIO引脚，PA1和PC13，PA1用于控制等待配置完成，然后请自行添加PC13的信号(等到PA1高电平来)即侵入信号。
• 实验结果应该是备份域被复位，读出数据为0x0。

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总结

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参考资料

[1]. MM32 miniboard资料