//============================================================================
//函数名称：CANInit
//函数返回：0：成功；1：失败
//参数说明：
// CANChannel：模块号
// baudrateKHz: 波特率
// selfLoop: 模式选择(1=回环模式；0=正常模式)
// idMask: ID过滤(1=ID过滤；0=ID不过滤)
//功能概要：CAN初始化
//============================================================================
uint8 CANInit(uint8 CANChannel,uint32 baudrateKHz,uint8 selfLoop,uint8 idMask)
{
int8 i;
CAN_MemMapPtr CANBaseAdd;
//使能FlexCAN外部时钟
OSC_CR |= OSC_CR_ERCLKEN_MASK | OSC_CR_EREFSTEN_MASK;
//通过模块号选择模块基地址
if(CANChannel == 0)
CANBaseAdd = CAN0_BASE_PTR;
else if(CANChannel == 1)
CANBaseAdd = CAN1_BASE_PTR;
//使能CAN模块时钟
if(CANBaseAdd == CAN0_BASE_PTR)
SIM_SCGC6 |= SIM_SCGC6_FLEXCAN0_MASK;//使能CAN0的时钟模块
else
SIM_SCGC3 |= SIM_SCGC3_FLEXCAN1_MASK;//使能CAN1的时钟模块
//使能CAN中断
if(CANChannel == 0)//使能CAN0的中断
{
NVICICPR0 = (NVICICPR0 & ~(0x07<<29)) | (0x07<<29);//清除挂载在FlexCAN0的中断
NVICISER0 = (NVICISER0 & ~(0x07<<29)) | (0x07<<29);//使能FlexCAN0中断
NVICICPR1 = (NVICICPR1 & ~(0x1F<<0)) | (0x1F);//清除挂载在FlexCAN0的中断
NVICISER1 = (NVICISER1 & ~(0x1F<<0)) | (0x1F);//使能FlexCAN0中断
}
else //使能CAN1的中断
{
NVICICPR1 = (NVICICPR1 & ~(0xFF<<5)) | (0xFF<<5);//清除挂载在FlexCAN1的中断
NVICISER1 = (NVICISER1 & ~(0xFF<<5)) | (0xFF<<5);//使能FlexCAN1中断
}
//配置CAN_RX/TX复用引脚功能
if(CANChannel == 0)
{
PORTA_PCR12 = PORT_PCR_MUX(2) | PORT_PCR_PE_MASK | PORT_PCR_PS_MASK; //上拉
PORTA_PCR13 = PORT_PCR_MUX(2) | PORT_PCR_PE_MASK | PORT_PCR_PS_MASK; //上拉
}
else
{
PORTE_PCR24 = PORT_PCR_MUX(2) | PORT_PCR_PE_MASK | PORT_PCR_PS_MASK; //Tx上拉
PORTE_PCR25 = PORT_PCR_MUX(2) | PORT_PCR_PE_MASK | PORT_PCR_PS_MASK; //Rx上拉
}
//选择时钟源，外设时钟48MHz，内部时钟：12MHz
CAN_CTRL1_REG(CANBaseAdd) |= CAN_CTRL1_CLKSRC_MASK;//选择内部时钟
CAN_MCR_REG(CANBaseAdd) |= CAN_MCR_FRZ_MASK; //使能冻结模式
CAN_MCR_REG(CANBaseAdd) &= ~CAN_MCR_MDIS_MASK;//使能CAN模块
//确认已退出冻结模式
while((CAN_MCR_LPMACK_MASK & CAN_MCR_REG(CANBaseAdd)));
//软件复位
CAN_MCR_REG(CANBaseAdd) ^= CAN_MCR_SOFTRST_MASK;
//等待复位完成
while(CAN_MCR_SOFTRST_MASK & CAN_MCR_REG(CANBaseAdd));
//等待进入冻结模式
while(!(CAN_MCR_FRZACK_MASK & CAN_MCR_REG(CANBaseAdd)));
//将16个邮箱缓冲区内容清0
for(i=0;i<16;i++)
{
CANBaseAdd->MB[i].CS = 0x00000000;
CANBaseAdd->MB[i].ID = 0x00000000;
CANBaseAdd->MB[i].WORD0 = 0x00000000;
CANBaseAdd->MB[i].WORD1 = 0x00000000;
}
//接收邮箱过滤IDE比较，RTR不比较
CAN_CTRL2_REG(CANBaseAdd) &= ~CAN_CTRL2_EACEN_MASK;
//远程请求帧产生
CAN_CTRL2_REG(CANBaseAdd) &= ~CAN_CTRL2_RRS_MASK;
//邮箱首先从接收FIFO队列匹配然后再在邮箱中匹配
CAN_CTRL2_REG(CANBaseAdd) &= ~CAN_CTRL2_MRP_MASK;
//使用一个32位过滤器
CAN_MCR_REG(CANBaseAdd) |= (CAN_MCR_REG(CANBaseAdd) & ~CAN_MCR_IDAM_MASK) | CAN_MCR_IDAM(0);
//设置波特率
if(SetCANBand(CANChannel,baudrateKHz) == 1)//若设置错误
return 1;
//模式选择：回环模式或正常模式
if(1==selfLoop)
CAN_CTRL1_REG(CANBaseAdd) |= CAN_CTRL1_LPB_MASK;//使用回环模式
//初始化掩码寄存器
if(1==idMask)//屏蔽ID
{
CAN_RXMGMASK_REG(CANBaseAdd) = 0x1FFFFFFF;
CAN_RX14MASK_REG(CANBaseAdd) = 0x1FFFFFFF;
CAN_RX15MASK_REG(CANBaseAdd) = 0x1FFFFFFF;
}
else//不屏蔽ID
{
CAN_RXMGMASK_REG(CANBaseAdd) = 0x0;
CAN_RX14MASK_REG(CANBaseAdd) = 0x0;
CAN_RX15MASK_REG(CANBaseAdd) = 0x0;
}
//如果单独掩码功能使能，为每个队列初始化单独的掩码寄存器
if(CAN_MCR_REG(CANBaseAdd) & CAN_MCR_IRMQ_MASK)
{
for(i = 0; i < NUMBER_OF_MB ; i++)
{
CANBaseAdd->RXIMR[i] = 0x1FFFFFFFL;
}
}
//只有在冻结模式下才能配置，配置完推出冻结模式
CAN_MCR_REG(CANBaseAdd) &= ~(CAN_MCR_HALT_MASK);
//等待直到退出冻结模式
while( CAN_MCR_REG(CANBaseAdd) & CAN_MCR_FRZACK_MASK);
//等到不在冻结模式，休眠模式或者停止模式
while((CAN_MCR_REG(CANBaseAdd) & CAN_MCR_NOTRDY_MASK));
return 0;
}
/***********************************************************************************************
功能：CAN 初始化
形参：CAN_InitStruct: CAN 初始化结构
返回：0
详解：0
************************************************************************************************/
void CAN_Init(CAN_InitTypeDef* CAN_InitStruct)
{
uint8_t i = 0;
PORT_Type *CAN_PORT = NULL;
CAN_MapTypeDef *pCAN_Map = (CAN_MapTypeDef*)&(CAN_InitStruct->CANxMap);
CAN_Type *CANx = NULL;
//参数检测
assert_param(IS_FUNCTIONAL_STATE(CAN_InitStruct->FilterEnable));
assert_param(IS_CAN_MAP(CAN_InitStruct->CANxMap));
assert_param(IS_CAN_SPEED(CAN_InitStruct->CAN_BaudRateSelect));
//找出CAN模块 开启CAN模块时钟
switch(pCAN_Map->CAN_Index )
{
case 0:
SIM->SCGC6 |= SIM_SCGC6_FLEXCAN0_MASK;
CANx = CAN0;
break;
case 1:
SIM->SCGC3 |= SIM_SCGC3_FLEXCAN1_MASK;
CANx = CAN1;
break;
default:break;
}
//找出对应的PORT
switch(pCAN_Map->CAN_GPIO_Index)
{
case 0:
SIM->SCGC5 |= SIM_SCGC5_PORTA_MASK;
CAN_PORT = PORTA;
break;
case 1:
SIM->SCGC5 |= SIM_SCGC5_PORTB_MASK;
CAN_PORT = PORTB;
break;
case 2:
SIM->SCGC5 |= SIM_SCGC5_PORTC_MASK;
CAN_PORT = PORTC;
break;
case 3:
SIM->SCGC5 |= SIM_SCGC5_PORTD_MASK;
CAN_PORT = PORTD;
break;
case 4:
SIM->SCGC5 |= SIM_SCGC5_PORTE_MASK;
CAN_PORT = PORTE;
break;
default:break;
}
//开启对应的引脚
CAN_PORT->PCR[pCAN_Map->CAN_TX_Pin_Index] &= ~PORT_PCR_MUX_MASK;
CAN_PORT->PCR[pCAN_Map->CAN_RX_Pin_Index] &= ~PORT_PCR_MUX_MASK;
CAN_PORT->PCR[pCAN_Map->CAN_TX_Pin_Index] |= PORT_PCR_MUX(pCAN_Map->CAN_Alt_Index);
CAN_PORT->PCR[pCAN_Map->CAN_RX_Pin_Index] |= PORT_PCR_MUX(pCAN_Map->CAN_Alt_Index);
//选择为BusClock时钟
CANx->CTRL1 |= CAN_CTRL1_CLKSRC_MASK;
//使能冻结模式 只有进入冻结模式才能配置波特率
CANx->MCR|=CAN_MCR_FRZ_MASK;
//开启CAN通信模块
CANx->MCR &= ~CAN_MCR_MDIS_MASK;
//等待通信模块复位启动
while((CAN_MCR_LPMACK_MASK & (CANx->MCR)));
//软件复位模块 //等待软件复位完成
CANx->MCR |= CAN_MCR_SOFTRST_MASK;
while(CAN_MCR_SOFTRST_MASK & (CANx->MCR));
// 等待模块进入冻结模式
while(!(CAN_MCR_FRZACK_MASK & (CANx->MCR)));
for(i=0;i<16;i++)
{
CANx->MB[i].CS = 0x00000000;
CANx->MB[i].ID = 0x00000000;
CANx->MB[i].WORD0 = 0x00000000;
CANx->MB[i].WORD1 = 0x00000000;
}
//配置远程请求产生，接收邮箱过滤ide，远程请求不比较，
//邮箱首先从接收fifo匹配后再邮箱中匹配见参考手册
CANx->CTRL2 = (0|CAN_CTRL2_TASD(22));
//配置ID模式，目前选择的是A格式
//按照工作要求配置MCR寄存器
CANx->MCR |= CAN_MCR_IDAM(0);
//使能个别滤波和接受队列特点?
//配置通信频率和初始化CTRL1 （自己理解的，设置传输一bite的时间） |CAN_CTRL1_LPB_MASK
CANx->MCR |= CAN_MCR_IRMQ_MASK;
//设置传输速率
CAN_SetBaudrate(CANx,CAN_InitStruct->CAN_BaudRateSelect);
CANx->MCR |= CAN_MCR_IDAM(0); //配置ID模式，目前选择的是A格式
//设置屏蔽功能
if(CAN_InitStruct->FilterEnable == ENABLE)
{
for(i = 0; i < 16 ; i++)
{
CANx->RXIMR[i] = 0x1FFFFFFF; //设置16个接收id的掩码寄存器
CANx->RXMGMASK = 0x1FFFFFFF;
}
}
else
{
for(i = 0; i < 16 ; i++)
{
CANx->RXIMR[i] = 0; //设置16个接收id的掩码寄存器
CANx->RXMGMASK = 0;
}
}
//只有在冻结模式下才能配置 配置完退出冻结模式
CANx->MCR &= ~(CAN_MCR_HALT_MASK);
//等待模块推出冻结模式
while((CAN_MCR_FRZACK_MASK & (CANx->MCR)));
//等待同步
while(((CANx->MCR)&CAN_MCR_NOTRDY_MASK));
//设置接收ID过滤功能
}
