void CAN_Init(void)
{
SIM_SCGC6|=SIM_SCGC6_FLEXCAN0_MASK;
PORTA_PCR13=PORT_PCR_MUX(0x02);
PORTA_PCR12=PORT_PCR_MUX(0x02);
CAN0_MCR|=CAN_MCR_FRZ_MASK;
CAN0_MCR&=~CAN_MCR_MDIS_MASK;
while(CAN0_MCR&CAN_MCR_LPMACK_MASK);
CAN0_MCR|=CAN_MCR_SOFTRST_MASK;
while(CAN0_MCR&CAN_MCR_SOFTRST_MASK);
while(!(CAN0_MCR&CAN_MCR_FRZACK_MASK));
CAN0_MCR|=CAN_MCR_SRXDIS_MASK;
CAN0_MCR|=CAN_MCR_RFEN_MASK;
CAN0_CTRL1=CAN_CTRL1_PROPSEG(2)|CAN_CTRL1_RJW(1)|CAN_CTRL1_PSEG1(7)|CAN_CTRL1_PSEG2(3)|CAN_CTRL1_PRESDIV(1); // 500KBPS
// CAN0_CTRL1=CAN_CTRL1_PROPSEG(2)|CAN_CTRL1_RJW(1)|CAN_CTRL1_PSEG1(7)|CAN_CTRL1_PSEG2(3)|CAN_CTRL1_PRESDIV(9); // 100KBPS
CAN0_CTRL1&=~CAN_CTRL1_LPB_MASK;
CAN0_RXIMR0=CAN_RXIMR_MI(0x1FFFFFFF);
CAN0_RXMGMASK=0;
CAN0_RXFGMASK=0;
CAN0_MCR&=~CAN_MCR_HALT_MASK;
while(CAN0_MCR&CAN_MCR_FRZACK_MASK);
while(CAN0_MCR&CAN_MCR_NOTRDY_MASK);
CAN0_CS(txb)=CAN_CS_CODE(0/*INACTIVE*/);
}
/***********************************************************************************************
功能：CAN 设置波特率
形参：CAN_Type: CAN结构
@arg CAN0 : CAN0模块
@arg CAN1 : CAN1模块
baudrate: 波特率
@arg CAN_SPEED_33K
@arg CAN_SPEED_83K
@arg CAN_SPEED_50K
@arg CAN_SPEED_100K
@arg CAN_SPEED_125K
@arg CAN_SPEED_250K
@arg CAN_SPEED_500K
@arg CAN_SPEED_1000K
返回：0
详解：0
************************************************************************************************/
static uint8_t CAN_SetBaudrate(CAN_Type *can,uint8_t baudrate)
{
switch(baudrate)
{
case CAN_SPEED_33K:
// 48M/120= 400k sclock, 12Tq
// PROPSEG = 3, LOM = 0x0, LBUF = 0x0, TSYNC = 0x0, SAMP = 1
// RJW = 3, PSEG1 = 4, PSEG2 = 4,PRESDIV = 120
can->CTRL1 = (0 | CAN_CTRL1_PROPSEG(2)
| CAN_CTRL1_RJW(2)
| CAN_CTRL1_PSEG1(3)
| CAN_CTRL1_PSEG2(3)
| CAN_CTRL1_PRESDIV(119));
break;
case CAN_SPEED_83K:
// 48M/48= 1M sclock, 12Tq
// PROPSEG = 3, LOM = 0x0, LBUF = 0x0, TSYNC = 0x0, SAMP = 1
// RJW = 3, PSEG1 = 4, PSEG2 = 4,PRESDIV = 48
can->CTRL1 = (0 | CAN_CTRL1_PROPSEG(2)
| CAN_CTRL1_RJW(2)
| CAN_CTRL1_PSEG1(3)
| CAN_CTRL1_PSEG2(3)
| CAN_CTRL1_PRESDIV(47));
break;
case CAN_SPEED_50K:
// 48M/80= 0.6M sclock, 12Tq
// PROPSEG = 3, LOM = 0x0, LBUF = 0x0, TSYNC = 0x0, SAMP = 1
// RJW = 3, PSEG1 = 4, PSEG2 = 4, PRESDIV = 40
can->CTRL1 = (0 | CAN_CTRL1_PROPSEG(2)
| CAN_CTRL1_RJW(1)
| CAN_CTRL1_PSEG1(3)
| CAN_CTRL1_PSEG2(3)
| CAN_CTRL1_PRESDIV(79));
break;
case CAN_SPEED_100K:
// 48M/40= 1.2M sclock, 12Tq
// PROPSEG = 3, LOM = 0x0, LBUF = 0x0, TSYNC = 0x0, SAMP = 1
// RJW = 3, PSEG1 = 4, PSEG2 = 4, PRESDIV = 40
can->CTRL1 = (0 | CAN_CTRL1_PROPSEG(2)
| CAN_CTRL1_RJW(2)
| CAN_CTRL1_PSEG1(3)
| CAN_CTRL1_PSEG2(3)
| CAN_CTRL1_PRESDIV(39));
break;
case CAN_SPEED_125K:
// 48M/32= 1.5M sclock, 12Tq
// PROPSEG = 3, LOM = 0x0, LBUF = 0x0, TSYNC = 0x0, SAMP = 1
// RJW = 3, PSEG1 = 4, PSEG2 = 4, PRESDIV = 32
can->CTRL1 = (0 | CAN_CTRL1_PROPSEG(2)
| CAN_CTRL1_RJW(2)
| CAN_CTRL1_PSEG1(3)
| CAN_CTRL1_PSEG2(3)
| CAN_CTRL1_PRESDIV(31));
break;
case CAN_SPEED_250K:
// 48M/16= 3M sclock, 12Tq
// PROPSEG = 3, LOM = 0x0, LBUF = 0x0, TSYNC = 0x0, SAMP = 1
// RJW = 2, PSEG1 = 4, PSEG2 = 4, PRESDIV = 16
can->CTRL1 = (0 | CAN_CTRL1_PROPSEG(2)
| CAN_CTRL1_RJW(1)
| CAN_CTRL1_PSEG1(3)
| CAN_CTRL1_PSEG2(3)
| CAN_CTRL1_PRESDIV(15));
break;
case CAN_SPEED_500K:
// 48M/8=6M sclock, 12Tq
// PROPSEG = 3, LOM = 0x0, LBUF = 0x0, TSYNC = 0x0, SAMP = 1
// RJW = 2, PSEG1 = 4, PSEG2 = 4, PRESDIV = 6
can->CTRL1 = (0 | CAN_CTRL1_PROPSEG(2)
| CAN_CTRL1_RJW(1)
| CAN_CTRL1_PSEG1(3)
| CAN_CTRL1_PSEG2(3)
| CAN_CTRL1_PRESDIV(7));
break;
case CAN_SPEED_1000K:
// 48M/6=8M sclock
// PROPSEG = 4, LOM = 0x0, LBUF = 0x0, TSYNC = 0x0, SAMP = 1
// RJW = 1, PSEG1 = 1, PSEG2 = 2, PRESCALER = 6
can->CTRL1 = (0 | CAN_CTRL1_PROPSEG(3)
| CAN_CTRL1_RJW(0)
| CAN_CTRL1_PSEG1(0)
| CAN_CTRL1_PSEG2(1)
| CAN_CTRL1_PRESDIV(5));
break;
default: return 1;
}
return 0;
}