/*
* LPLD_I2C_Init
* I2C通用初始化函数
*
* 参数:
* i2cx--选择I2C模块号
* |__I2C0 --I2C0号模块
* |__I2C1 --I2C1号模块
* port--通道端口位选择
* |__0 --I2C0(PTB2-I2C0_SCL PTB3-I2C0_SDA)
* | --I2C1(PTE0-I2C1_SDA PTE1-I2C1_SCL)
* |__1 --I2C0(PTD8-I2C0_SCL PTD9-I2C0_SDA)
* | --I2C1(PTC10-I2C1_SCL PTC11-I2C1_SDA)
* scl_frq--选择IIC SCL频率
* |__I2C_SCL_50KHZ --50khz
* |__I2C_SCL_100KHZ --100khz
* |__I2C_SCL_150KHZ --150khz
* |__I2C_SCL_200KHZ --200khz
* |__I2C_SCL_250KHZ --250khz
* |__I2C_SCL_300KHZ --300khz
* 输出:
* 0--配置错误
* 1--配置成功
*/
uint8 LPLD_I2C_Init(I2Cx i2cx, uint8 port, uint8 scl_frq)
{
uint8 ps;
//参数检查
ASSERT( i2cx <= I2C1); //判断I2Cx模块号
ASSERT( scl_frq <= I2C_SCL_300KHZ); //判断SCL频率
ASSERT( port <= 1); //判断端口选择
//总线频率50mhz
//scl_frq=50mhz/(mul * scl div)
if(scl_frq == I2C_SCL_50KHZ)
{
ps=0x33;
}
else if(scl_frq == I2C_SCL_100KHZ)
{
ps=0x2B;
}
else if(scl_frq == I2C_SCL_150KHZ)
{
ps=0x28;
}
else if(scl_frq == I2C_SCL_200KHZ)
{
ps=0x23;
}
else if(scl_frq == I2C_SCL_250KHZ)
{
ps=0x21;
}
else if(scl_frq == I2C_SCL_300KHZ)
{
ps=0x20;
}
else
return 0;
if(i2cx==I2C0)
{
if(!port)
{
/* configure GPIO for I2C0 function */
PORTB_PCR2 = PORT_PCR_MUX(2);
PORTB_PCR3 = PORT_PCR_MUX(2);
}
else if(port==1)
{
/* configure GPIO for I2C0 function */
PORTD_PCR8 = PORT_PCR_MUX(2);
PORTD_PCR9 = PORT_PCR_MUX(2);
}
else
return 0;
SIM_SCGC4 |= SIM_SCGC4_I2C0_MASK; //开启I2C0时钟
}
else if(i2cx==I2C1)
{
if(!port)
{
/* configure GPIO for I2C0 function */
PORTE_PCR0 = PORT_PCR_MUX(6);
PORTE_PCR1 = PORT_PCR_MUX(6);
}
else if(port==1)
{
/* configure GPIO for I2C0 function */
PORTC_PCR10 = PORT_PCR_MUX(2);
PORTC_PCR11 = PORT_PCR_MUX(2);
}
else
return 0;
SIM_SCGC4 |= SIM_SCGC4_I2C1_MASK; //开启IIC1时钟
}
else
return 0;
I2C_F_REG(I2Cx_Ptr[i2cx]) = ps;
I2C_C1_REG(I2Cx_Ptr[i2cx]) = I2C_C1_IICEN_MASK; //使能I2Cx
return 1;
}
/*!
* @brief I2C初始化，设置波特率
* @param I2Cn_e I2C模块(I2C0、I2C1)
* @param baud 期待的波特率
* @return 实际的波特率
* @since v5.0
* Sample usage: i2c_init(I2C0,400*1000); // 初始化I2C0，期待的波特率为400k
*/
uint32 i2c_init(I2Cn_e i2cn, uint32 baud)
{
if(i2cn == I2C0)
{
/* 开启时钟 */
#if defined(MK60DZ10)
SIM_SCGC4 |= SIM_SCGC4_I2C0_MASK; //开启 I2C0时钟
#elif defined( MK60F15)
SIM_SCGC4 |= SIM_SCGC4_IIC0_MASK; //开启 I2C0时钟
#endif
/* 配置 I2C0功能的 GPIO 接口 */
if(I2C0_SCL == PTB0)
port_init (PTB0, ALT2 | ODO | PULLUP );
else if(I2C0_SCL == PTB2)
port_init (PTB2, ALT2 | ODO | PULLUP );
else if(I2C0_SCL == PTD8)
port_init (PTD8, ALT2 | ODO | PULLUP );
else
ASSERT(0); //上诉条件都不满足，直接断言失败了，设置管脚有误？
if(I2C0_SDA == PTB1)
port_init (PTB1, ALT2 | ODO | PULLUP );
else if(I2C0_SDA == PTB3)
port_init (PTB3, ALT2 | ODO | PULLUP );
else if(I2C0_SDA == PTD9)
port_init (PTD9, ALT2 | ODO | PULLUP );
else
ASSERT(0); //上诉条件都不满足，直接断言失败了，设置管脚有误？
}
else
{
/* 开启时钟 */
#if defined(MK60DZ10)
SIM_SCGC4 |= SIM_SCGC4_I2C1_MASK; //开启 I2C1时钟
#elif defined(MK60F15)
SIM_SCGC4 |= SIM_SCGC4_IIC1_MASK; //开启 I2C1时钟
#endif
/* 配置 I2C1功能的 GPIO 接口 */
if(I2C1_SCL == PTE1)
port_init (PTE1, ALT6 | ODO | PULLUP );
else if(I2C1_SCL == PTC10)
port_init (PTC10, ALT2 | ODO | PULLUP );
else
ASSERT(0); //上诉条件都不满足，直接断言失败了，设置管脚有误？
if(I2C1_SDA == PTE0)
port_init (PTE0, ALT6 | ODO | PULLUP );
else if (I2C1_SDA == PTC11)
port_init (PTC11, ALT2 | ODO | PULLUP );
else
ASSERT(0); //上诉条件都不满足，直接断言失败了，设置管脚有误？
}
/* 设置频率 */
// I2C baud rate = bus speed (Hz)/(mul × SCL divider) 即这里 50MHz/(1 ×128)=390.625kHz
// SDA hold time = bus period (s) × mul × SDA hold value
// SCL start hold time = bus period (s) × mul × SCL start hold value
// SCL stop hold time = bus period (s) × mul × SCL stop hold value
//查表 ICR 对应的 SCL_divider ，见 《K60P144M100SF2RM.pdf》第1468页的 I2C Divider and Hold Values
uint16 ICR_2_SCL_divider[0x40] =
{
20, 22, 24, 26, 28, 30, 34, 40, 28, 32, 36, 40, 44, 48, 56, 68,
48, 56, 64, 72, 80, 88, 104, 128, 80, 96, 112, 128, 144, 160, 192, 240,
160, 192, 224, 256, 288, 320, 384, 480, 320, 384, 448, 512, 576, 640, 768, 960,
640, 768, 896, 1024, 1152, 1280, 1536, 1920, 1280, 1536, 1792, 2048, 2304, 2560, 3072, 3840
};
uint8 mult;
if(bus_clk_khz <= 50000)mult = 0; //bus 一分频
else if(bus_clk_khz <= 100000)mult = 1; //bus 二分频
else mult = 2; //bus 四分频
uint16 scldiv = bus_clk_khz * 1000 / ( (mult + 1) * baud ); //最佳的分频系数
//需要从 ICR_2_SCL_divider 里找到 与最佳分频系数scldiv最相近的 分频系数
uint8 icr, n = 0x40;
uint16 min_Dvalue = ~0, Dvalue;
while(n) //循环里逐个扫描，找出最接近的 分频系数
{
n--;
Dvalue = abs(scldiv - ICR_2_SCL_divider[n]);
if(Dvalue == 0)
{
icr = n;
break; //退出while循环
}
if(Dvalue < min_Dvalue)
{
icr = n;
min_Dvalue = Dvalue;
}
}
I2C_F_REG(I2CN[i2cn]) = ( 0 // I2C Frequency Divider register (I2Cx_F) I2C分频寄存器 I2C最大波特率为 400k
| I2C_F_MULT(mult) // 乘数因子 mul = MULT + 1
| I2C_F_ICR(icr) // 时钟速率 = ICR_2_SCL_divider[ICR] ，查表获得 ICR 与 SCL_divider 映射关系
);
/* 使能 IIC1 */
I2C_C1_REG(I2CN[i2cn]) = ( 0
| I2C_C1_IICEN_MASK //使能I2C
//| I2C_C1_IICIE_MASK //使能中断
);
return ( bus_clk_khz * 1000 / ( (mult + 1) * ICR_2_SCL_divider[icr]) );
}
