C - 在闪存中存储全局变量？

Question

正如标题所暗示的，我目前在我的程序中缺少 SRAM，而且我找不到减少全局变量的方法。是否可以将全局变量带到闪存中？由于这些变量是频繁读写的，是否会因为nand flash的读写次数有限而对它们不利？

如果闪存不能处理这个问题，EEPROM 会是一个不错的选择吗？

编辑:对不起，模棱两可的家伙。我正在使用 Atmel AVR ATmega32HVB，它具有: 2K字节的SRAM， 1K字节的EEPROM 32K字节的FLASH

编译器:AVR C/C++

平台:IAR 嵌入式 AVR

我想去掉的全局变量是:

uint32_t capacityInCCAccumulated[TOTAL_CELL];

和

int32_t AccumulatedCCADCvalue[TOTAL_CELL]; 

代码片段:

  int32_t AccumulatedCCADCvalue[TOTAL_CELL];
    void CCGASG_AccumulateCCADCMeasurements(int32_t ccadcMeasurement, uint16_t slowRCperiod)
{ 
    uint8_t cellIndex;
    // Sampling period dependant on configuration of CCADC sampling..
    int32_t temp = ccadcMeasurement * (int32_t)slowRCperiod;

    bool polChange = false;
    if(temp < 0) {
        temp = -temp;
        polChange = true;
    }

    // Add 0.5*divisor to get proper rounding
    temp += (1<<(CCGASG_ACC_SCALING-1));
    temp >>= CCGASG_ACC_SCALING;

    if(polChange) {
        temp = -temp;
    }
    for (cellIndex = 0; cellIndex < TOTAL_CELL; cellIndex++)
    {
        AccumulatedCCADCvalue[cellIndex] += temp;
    }

    // If it was a charge, update the charge cycle counter
    if(ccadcMeasurement <= 0) {
        // If it was a discharge, AccumulatedCADCvalue can be negative, and that
        // is "impossible", so set it to zero
        for (cellIndex = 0; cellIndex < TOTAL_CELL; cellIndex++)
        {
            if(AccumulatedCCADCvalue[cellIndex] < 0) 
            {
                AccumulatedCCADCvalue[cellIndex] = 0;
            }
        }
    }   
}

还有这个

uint32_t capacityInCCAccumulated[TOTAL_CELL];
void BATTPARAM_InitSramParameters() {
        uint8_t cellIndex;
        // Active current threshold in ticks
    battParams_sram.activeCurrentThresholdInTicks = (uint16_t) BATTCUR_mA2Ticks(battParams.activeCurrentThreshold);

        for (cellIndex = 0; cellIndex < TOTAL_CELL; cellIndex++) 
        {
    // Full charge capacity in CC accumulated
            battParams_sram.capacityInCCAccumulated[cellIndex] = (uint32_t) CCGASG_mAh2Acc(battParams.fullChargeCapacity);
    }
    // Terminate discharge limit in CC accumulated
    battParams_sram.terminateDischargeLimit = CCGASG_mAh2Acc(battParams.terminateDischargeLimit);

    // Values for remaining capacity calibration
    GASG_CalculateRemainingCapacityValues();
}

Answer 1

would it be bad for the nand flash because they have limited number of read/write cycle?

是的，频繁修改数据时使用闪存不是一个好主意。只读闪存不会减少闪存的使用生命周期。删除和写入会缩短闪存生命周期。

与传统内存相比，从闪存读取和写入速度要慢得多。

要写入一个字节，必须删除整个 block 并重新写入闪存。