[参考译文] MSPM0G3519：尝试根据标准 IEEE 802.3多项式运行 CRCP

尊敬的 CY：

它是一个硬件加速器。

[报价用户 id="100134" url="~/support/microcontrollers/arm-based-microcontrollers-group/arm-based-microcontrollers/f/arm-based-microcontrollers-forum/1474669/mspm0g3519-trying-to-run-crcp-against-a-standard-ieee-802-3-polynomial "]

• CRCP 是通过 CRC 引擎逐字节流式传输32b 数据、还是使用整个32b 值？
• 对于如何配置 CRCP 以获得正确的答案、是否有任何提示或建议、或者是否有一些解释 CRCP CRC 引擎如何工作的伪代码？

[报价]

无论它在低电平下如何工作、我们都可以将其视为输入-输出模型。

有关如何在软件代码中实现的信息、请参阅 SDK 演示工程、其中还包括用于实现此目的的 DMA 方法。

https://dev.ti.com/tirex/explore/node?node=A__ALAN0bj6VmKQrgGhjKb.Eg__MSPM0-SDK__a3PaaoK__LATEST 

它是 CRC16演示、虽然可以轻松迁移到 CRC32。

需要注意以下几种配置：

1.CRC-32设置：

2.搜索值(初始化值)

我不确定  IEEE 802.3是什么、而我使用 JAMCCRC 对其进行了测试、输入为 字符串｛"1"、"2"、"3"、"5"、"6"、"6"、"7"、"8"｝

输出为"0x651F2550"、这是 CRC 输入字符串的正确结果。

B.R.

SAL

尊敬的 Eugene：

[报价 USERID="636987" URL="~/support/microcontrollers/arm-based-microcontrollers-group/arm-based-microcontrollers/f/arm-based-microcontrollers-forum/1474669/mspm0g3519-trying-to-run-crcp-against-a-standard-ieee-802-3-polynomial/5662350 #5662350"]下表中的"检查 CRC"表示 ASCII 值"1""2""3""3""4""5""6""7""8"对应于值31h 32h 33h 34h
35h 36h 37h 38h 39h 逐字节通过指定的算法馈送。

我‘了"1-8"的输入、由于 CL 在主题中询问了这一点：

[报价 userid="100134" url="~/support/microcontrollers/arm-based-microcontrollers-group/arm-based-microcontrollers/f/arm-based-microcontrollers-forum/1474669/mspm0g3519-trying-to-run-crcp-against-a-standard-ieee-802-3-polynomial "] 我们的客户正在尝试 针对标准 IEEE 802.3 "0x04C11DB7"多项式和测试字符串｛'1'、'2'、'3'、'4'、'5'、'6'、'7'、'8'｝运行 CRCP。 这将生成0xE3C97CBC CRC。 但无法真正使其正常工作。

我认为这是正确的价值：

因此、您可以从这边得出一个结论是正确的、最终 XOR 运算不在硬件这边执行。

我使用了示例工程、并将其修改为 CRC-32 (SysConfig 文件)：

/*
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#include "ti_msp_dl_config.h"

#define CRCP_NUM_OF_WORDS (8)
#define CRCP_EXPECTED_RESULT (0x651F2550)
uint8_t gData8[CRCP_NUM_OF_WORDS] = {'1', '2', '3', '4', '5', '6', '7', '8'};

const uint32_t gCrcpSeed            = CRCP_SEED;
volatile bool gCheckCRCP;

int main(void)
{
    volatile uint32_t crcpChecksum;
    __attribute__((unused)) volatile bool crcpChecksumMatch;

    SYSCFG_DL_init();

    /* Configure DMA source, destination and size */
    DL_DMA_setSrcAddr(DMA, DMA_CH0_CHAN_ID, (uint32_t) &gData8[0]);
    DL_DMA_setDestAddr(DMA, DMA_CH0_CHAN_ID, DL_CRCP_getCRCINAddr(CRCP0));
    DL_DMA_setTransferSize(
        DMA, DMA_CH0_CHAN_ID, sizeof(gData8) / sizeof(uint8_t));
    DL_DMA_enableChannel(DMA, DMA_CH0_CHAN_ID);

    /*
     * Confirm DMA channel is enabled before issuing a SW trigger of the DMA
     * channel
     */
    while (false == DL_DMA_isChannelEnabled(DMA, DMA_CH0_CHAN_ID)) {
        __BKPT(0);
    }

    /* Configure device exception handling */
    DL_SYSCTL_disableSleepOnExit();
    NVIC_EnableIRQ(DMA_INT_IRQn);
    gCheckCRCP = false;

    /* Trigger DMA via SW request */
    DL_DMA_startTransfer(DMA, DMA_CH0_CHAN_ID);

    /* Wait in SLEEP mode until DMA interrupt is triggered */
    while (false == gCheckCRCP) {
        __WFE();
    }

    /* Check CRCP checksum */
    crcpChecksum = DL_CRCP_getResult32(CRCP0);

    if (CRCP_EXPECTED_RESULT == crcpChecksum) {
        crcpChecksumMatch = true;
        DL_GPIO_clearPins(GPIO_LEDS_PORT, GPIO_LEDS_USER_LED_1_PIN);
    } else {
        crcpChecksumMatch = false;
    }

    __BKPT(0);

    while (1) {
        __WFI();
    }
}

void DMA_IRQHandler(void)
{
    switch (DL_DMA_getPendingInterrupt(DMA)) {
        case DL_DMA_EVENT_IIDX_DMACH0:
            gCheckCRCP = true;
            break;
        default:
            break;
    }
}

然后、您可以在不使用 SysConfig 的情况下对其进行修改、其中随附了示例项目的所有代码。

[报价 userid="636987" url="~/support/microcontrollers/arm-based-microcontrollers-group/arm-based-microcontrollers/f/arm-based-microcontrollers-forum/1474669/mspm0g3519-trying-to-run-crcp-against-a-standard-ieee-802-3-polynomial/5662350 #5662350"]

• 当使用32位数(LE) 0x31323334和0x3536373839将数据馈入 CRCP 后、结果是否会改变？
• 如果32位量位于0x34333231和0x3938373635中、将发生什么变化？

[报价]

您可以根据项目进行尝试。 我认为#2将输出相同的结果、而#3将不会输出相同的结果。

B.R.

SAL