S9KEAZ128 CAN发送和接收过滤方法程序

以下是使用S9KEAZ128芯片进行CAN发送和接收过滤的示例程序：

#include "SKEAZ1284.h"

#define CAN0_BASE_PTR SKEAZN1284
#define CAN1_BASE_PTR SKEAZN1284

void CAN0_Init(void) {
    // Enable clock for CAN0 module
    SIM_SCGC |= SIM_SCGC_CAN0_MASK;
    
    // Configure pins for CAN0
    // Set pins to alternative function mode
    PORTA_PCR12 |= PORT_PCR_MUX(2); // CAN0_TX
    PORTA_PCR13 |= PORT_PCR_MUX(2); // CAN0_RX
    
    // Configure CAN0 module
    CAN0_MCR |= CAN_MCR_FRZ_MASK; // Enter freeze mode
    CAN0_MCR &= ~CAN_MCR_MDIS_MASK; // Enable module
    CAN0_MCR |= CAN_MCR_IRMQ_MASK; // Individual Rx masking
    CAN0_MCR |= CAN_MCR_AEN_MASK; // Enable Rx ID acceptance filter
    CAN0_CTRL1 |= CAN_CTRL1_CLKSRC_MASK | CAN_CTRL1_CANEN_MASK; // Use oscillator clock
    
    // Set bit rate for CAN0
    CAN0_CTRL1 |= CAN_CTRL1_PROPSEG(2) | CAN_CTRL1_PSEG1(1) |
                  CAN_CTRL1_PSEG2(1) | CAN_CTRL1_PRESDIV(4);
    
    // Enable interrupts for CAN0
    CAN0_IMASK1 |= CAN_IMASK1_BUF0M_MASK; // Enable buffer 0 interrupt
    NVICICPR0 |= (1 << 19); // Clear pending interrupts
    NVICISER0 |= (1 << 19); // Enable interrupts
}

void CAN0_FilterInit(void) {
    // Configure filter 0 for standard ID
    CAN0_RXIMR0 |= CAN_RXIMR0_MI(0); // Enable filter 0
    CAN0_RXMGMASK |= CAN_RXMGMASK_MG(0); // Match filter 0
    
    // Configure filter 1 for extended ID
    CAN0_RXIMR1 |= CAN_RXIMR1_MI(1); // Enable filter 1
    CAN0_RXMGMASK |= CAN_RXMGMASK_MG(1); // Match filter 1
    
    // Set ID for filter 0 and filter 1
    CAN0_RXFGMASK = 0xFF; // Match all bits
    CAN0_IDFLT_TAB[0] = 0x123; // Set filter 0 ID
    CAN0_IDFLT_TAB[1] = 0x456; // Set filter 1 ID
}

void CAN0_Send(uint32_t id, uint8_t *data, uint8_t length) {
    // Wait for transmit buffer 0 to be empty
    while (!(CAN0_IFLAG1 & CAN_IFLAG1_BUF0I_MASK));
    
    // Set ID and length
    CAN0_IFLAG1 |= CAN_IFLAG1_BUF0I_MASK; // Clear interrupt flag
    CAN0_MBn_ID(0) = id; // Set ID
    CAN0_MBn_CS(0) = CAN_CS_CODE(CAN_TX_IN_PROGRESS) | CAN_CS_LENGTH(length); // Set length
    
    // Set data
    for (uint8_t i = 0; i < length; i++) {
        CAN0_MBn_DATA_BYTE(0, i) = data[i];
    }
    
    // Start transmission
    CAN0_MBn_CS(0) |= CAN_CS_CODE(CAN_TX_TRANSMIT);
}

void CAN0_Receive(void) {
    // Check if buffer 4 has received a message
    if (CAN0_IFLAG1 & CAN_IFLAG1_BUF4I_MASK) {
        // Read ID and length
        uint32_t id = CAN0_MBn_ID(4);
        uint8_t length = CAN0_MBn_CS(4) & CAN_CS_LENGTH_MASK;
        
        // Read data
        uint8_t data[8];
        for (uint8_t i = 0; i < length; i++) {
            data[i] = CAN0_MBn_DATA_BYTE(4, i);
        }
        
        // Process received message
        
        // Clear interrupt flag
        CAN0_IFLAG1 |= CAN_IFLAG1_BUF4I_MASK;
    }
}

void CAN0_IRQHandler(void) {
    CAN0_Receive();
}

int main(void) {
    // Initialize CAN0 module
    CAN0_Init();
    
    // Initialize CAN0 filters
    CAN0_FilterInit();
    
    // Enable interrupts
    __enable_irq();
    
    while (1) {
        // Send a CAN message
        uint8_t data[] = {0x01, 0x02, 0x03};
        CAN0_Send(0x123, data, sizeof(data));
        
        // Delay
        for (volatile uint32_t i = 0; i < 1000000; i++);
    }
}

这是一个使用S9KEAZ128芯片的CAN发送和接收过滤的示例程序。首先，我们初始化CAN0模块并配置相关引脚。然后，我们设置CAN0模块的位速率，并启用中断。接下来，我们初始化CAN0过滤器，设置过滤器ID。然后，我们实现CAN0的发送函数，该函数将数据发送到CAN总线上。最后，我们实现CAN0的接收函数，该函数从CAN总线上接收数据并进行处理。

在main函数中，我们首先初始化CAN0模块和过滤器，然后启用中断。然后，我们进入一个无限循环，在该循环中发送CAN消息并延迟一段时间