示例#1
0
文件: i2c.c 项目: Jlassi/coldfire
/*
 * Initializes I2C0
 */
void i2c_init() {
	// Initialize DMA timer for use in transfer delays
	dtim0_init();
	
	// Configure GPIO port AS for SCL and SDA
	MCF_GPIO_PASPAR |= MCF_GPIO_PASPAR_SCL0_SCL0;
	MCF_GPIO_PASPAR |= MCF_GPIO_PASPAR_SDA0_SDA0;
	
	// Do we need data direction as output?
	/*MCF_GPIO_DDRAS |= MCF_GPIO_DDRAS_DDRAS0;
	MCF_GPIO_DDRAS |= MCF_GPIO_DDRAS_DDRAS1;*/
	
	// Write the I2C board address
	MCF_I2C0_I2ADR |= MCF_I2C_I2ADR_ADR(I2C_ADDR);
	
	// Write the i2c clock rate. f_i2c = 80Mhz / divider
	// divider = 80Mhz / 0.1 Mhz = 800. Closest divider in Table 29.2 896 for 89.29Khz, IC = 0x3A
	MCF_I2C0_I2FDR |= MCF_I2C_I2FDR_IC(0x3A);
	
	// Reset to slave-receiver mode
	i2c_reset();
	
	// If the bus is busy b/c a slave is transmitting, generate a stop bit when switching
	// from master-recviver back to slave-receiver
	if(MCF_I2C0_I2SR & MCF_I2C_I2SR_IBB) {
		MCF_I2C0_I2CR = 0x00; // Board is slave-receiver, i2c disabled, interrupts disabled
		MCF_I2C0_I2CR = 0xA0; // Board is master-receiver, i2c enabled, interrupts, disabled
		uint8_t dummy = MCF_I2C0_I2DR; // Dummy read from slave which is transmitting
		MCF_I2C0_I2SR = 0x00; // Clear arbitration lost flag, clear i2c interrupt request flag
		MCF_I2C0_I2CR = 0x00; // Board is slave-receiver, i2c disabled, interrupts disabled
		MCF_I2C0_I2CR = 0x80; // Enable I2C module
	}
}
示例#2
0
void fst_nunchuk_init(){
	
	dtim0_init();
	i2c_init(); //100 kHz

	
	
}