//Initialize as a slave
void TwoWire::begin(uint8_t address)
{
if(i2cModule == NOT_ACTIVE) {
i2cModule = BOOST_PACK_WIRE;
}
ROM_SysCtlPeripheralEnable(g_uli2cPeriph[i2cModule]);
ROM_GPIOPinConfigure(g_uli2cConfig[i2cModule][0]);
ROM_GPIOPinConfigure(g_uli2cConfig[i2cModule][1]);
ROM_GPIOPinTypeI2C(g_uli2cBase[i2cModule], g_uli2cSDAPins[i2cModule]);
ROM_GPIOPinTypeI2CSCL(g_uli2cBase[i2cModule], g_uli2cSCLPins[i2cModule]);
slaveAddress = address;
//Enable slave interrupts
ROM_IntEnable(g_uli2cInt[i2cModule]);
I2CSlaveIntEnableEx(SLAVE_BASE, I2C_SLAVE_INT_DATA | I2C_SLAVE_INT_STOP);
HWREG(SLAVE_BASE + I2C_O_SICR) =
I2C_SICR_DATAIC | I2C_SICR_STARTIC | I2C_SICR_STOPIC;
//Setup as a slave device
ROM_I2CMasterDisable(MASTER_BASE);
I2CSlaveEnable(SLAVE_BASE);
I2CSlaveInit(SLAVE_BASE, address);
ROM_IntMasterEnable();
}
int main(void) {
SysCtlClockSet(SYSCTL_SYSDIV_4 | SYSCTL_USE_PLL | SYSCTL_XTAL_16MHZ | SYSCTL_OSC_MAIN);
SysCtlDelay(10000);
SysCtlPeripheralEnable(SYSCTL_PERIPH_GPIOD);
GPIOPinTypeI2CSCL(GPIO_PORTD_BASE, GPIO_PIN_0);
GPIOPinTypeI2C(GPIO_PORTD_BASE, GPIO_PIN_1);
GPIOPinConfigure(GPIO_PD0_I2C3SCL);
GPIOPinConfigure(GPIO_PD1_I2C3SDA);
SysCtlPeripheralEnable(SYSCTL_PERIPH_I2C3);
I2CSlaveInit(I2C3_SLAVE_BASE, I2C_SLAVE_ADDRESS);
I2CSlaveAddressSet(I2C3_SLAVE_BASE, I2C_SLAVE_ADDRESS, 0);
I2CSlaveIntEnableEx(I2C3_SLAVE_BASE, I2C_SLAVE_INT_START|I2C_SLAVE_INT_STOP|I2C_SLAVE_INT_DATA);
I2CSlaveEnable(I2C3_SLAVE_BASE);
IntEnable(INT_I2C3);
IntMasterEnable();
while(1) {
SysCtlDelay(100000);
}
}
//*****************************************************************************
//
// Configure the I2C0 master and slave and connect them using loopback mode.
//
//*****************************************************************************
int
main(void)
{
uint32_t ui32DataTx;
//
// Set the clocking to run directly from the external crystal/oscillator.
// TODO: The SYSCTL_XTAL_ value must be changed to match the value of the
// crystal on your board.
//
SysCtlClockSet(SYSCTL_SYSDIV_1 | SYSCTL_USE_OSC | SYSCTL_OSC_MAIN |
SYSCTL_XTAL_16MHZ);
//
// The I2C0 peripheral must be enabled before use.
//
SysCtlPeripheralEnable(SYSCTL_PERIPH_I2C0);
//
// For this example I2C0 is used with PortB[3:2]. The actual port and
// pins used may be different on your part, consult the data sheet for
// more information. GPIO port B needs to be enabled so these pins can
// be used.
// TODO: change this to whichever GPIO port you are using.
//
SysCtlPeripheralEnable(SYSCTL_PERIPH_GPIOB);
//
// Configure the pin muxing for I2C0 functions on port B2 and B3.
// This step is not necessary if your part does not support pin muxing.
// TODO: change this to select the port/pin you are using.
//
GPIOPinConfigure(GPIO_PB2_I2C0SCL);
GPIOPinConfigure(GPIO_PB3_I2C0SDA);
//
// Select the I2C function for these pins. This function will also
// configure the GPIO pins pins for I2C operation, setting them to
// open-drain operation with weak pull-ups. Consult the data sheet
// to see which functions are allocated per pin.
// TODO: change this to select the port/pin you are using.
//
GPIOPinTypeI2C(GPIO_PORTB_BASE, GPIO_PIN_2 | GPIO_PIN_3);
//
// Enable loopback mode. Loopback mode is a built in feature that helps
// for debug the I2Cx module. It internally connects the I2C master and
// slave terminals, which effectively lets you send data as a master and
// receive data as a slave. NOTE: For external I2C operation you will need
// to use external pull-ups that are faster than the internal pull-ups.
// Refer to the datasheet for more information.
//
HWREG(I2C0_BASE + I2C_O_MCR) |= 0x01;
//
// Enable the I2C0 interrupt on the processor (NVIC).
//
IntEnable(INT_I2C0);
//
// Configure and turn on the I2C0 slave interrupt. The I2CSlaveIntEnableEx()
// gives you the ability to only enable specific interrupts. For this case
// we are only interrupting when the slave device receives data.
//
I2CSlaveIntEnableEx(I2C0_BASE, I2C_SLAVE_INT_DATA);
//
// Enable and initialize the I2C0 master module. Use the system clock for
// the I2C0 module. The last parameter sets the I2C data transfer rate.
// If false the data rate is set to 100kbps and if true the data rate will
// be set to 400kbps. For this example we will use a data rate of 100kbps.
//
I2CMasterInitExpClk(I2C0_BASE, SysCtlClockGet(), false);
//
// Enable the I2C0 slave module.
//
I2CSlaveEnable(I2C0_BASE);
//
// Set the slave address to SLAVE_ADDRESS. In loopback mode, it's an
// arbitrary 7-bit number (set in a macro above) that is sent to the
// I2CMasterSlaveAddrSet function.
//
I2CSlaveInit(I2C0_BASE, SLAVE_ADDRESS);
//
// Tell the master module what address it will place on the bus when
// communicating with the slave. Set the address to SLAVE_ADDRESS
// (as set in the slave module). The receive parameter is set to false
// which indicates the I2C Master is initiating a writes to the slave. If
// true, that would indicate that the I2C Master is initiating reads from
// the slave.
//
I2CMasterSlaveAddrSet(I2C0_BASE, SLAVE_ADDRESS, false);
//
// Set up the serial console to use for displaying messages. This is just
// for this example program and is not needed for proper I2C operation.
//
InitConsole();
//
// Enable interrupts to the processor.
//
IntMasterEnable();
//
// Display the example setup on the console.
//
UARTprintf("I2C Slave Interrupt Example ->");
UARTprintf("\n Module = I2C0");
UARTprintf("\n Mode = Receive interrupt on the Slave module");
UARTprintf("\n Rate = 100kbps\n\n");
//
// Initialize the data to send.
//
ui32DataTx = 'I';
//
// Indicate the direction of the data.
//
UARTprintf("Transferring from: Master -> Slave\n");
//
// Display the data that I2C0 is transferring.
//
UARTprintf(" Sending: '%c'", ui32DataTx);
//
// Place the data to be sent in the data register.
//
I2CMasterDataPut(I2C0_BASE, ui32DataTx);
//
// Initiate send of single piece of data from the master. Since the
// loopback mode is enabled, the Master and Slave units are connected
// allowing us to receive the same data that we sent out.
//
I2CMasterControl(I2C0_BASE, I2C_MASTER_CMD_SINGLE_SEND);
//
// Wait for interrupt to occur.
//
while(!g_bIntFlag)
{
}
//
// Display that interrupt was received.
//
UARTprintf("\n Slave Interrupt Received!\n");
//
// Display the data that the slave has received.
//
UARTprintf(" Received: '%c'\n\n", g_ui32DataRx);
//
// Loop forever.
//
while(1)
{
}
}
