NET+OS 6.1 Training

1. NET+OS 6.1 Training NetSilicon & Digi Confidential

2. I2C NetSilicon & Digi Confidential

3. I2C device topics • Introduction • I2C APIs • I2C examples NetSilicon & Digi Confidential

4. I2C device basic • Simple 4-wire device. Multiple I2C devices can be connected to the same I2C bus. • We support two types (all) I2C devices – I2C Master and I2C Slave. NetSilicon & Digi Confidential

5. Performance • We support 100Kbits/sec or 400Kbits/sec. • Support 7 & 10 bit addressing • Dedicated I/O. No change to the gpio.h NetSilicon & Digi Confidential

6. IC2 Master Interface NetSilicon & Digi Confidential

7. I2C Slave NetSilicon & Digi Confidential

8. From master to slave 1. Received of slave side From slave to master S Slave Address RW A Data(8Bit) A Data(8Bit) A P 1 0 2. Transmitted of slave side S Slave Address RW A Data(8Bit) A Data(8Bit) A P S = Start A = ACK P = STOP / Repeat Start 7bit addressing format NetSilicon & Digi Confidential

9. From master to slave 1. Receivedof slave side From slave to master S Address Upper RW A Address Lower A Data(8Bit) A 0 1 0 Data(8Bit) Data(8Bit) A A P P 2. Transmitted of slave side S Address Upper RW A Address Lower A P Address Upper RW A S = Start A = ACK P = STOP / Repeat Start 10bit addressing format NetSilicon & Digi Confidential

10. Device Open() • Calls i2c_dev_open() • Example i2cPort = open("/i2c/0",I2C_SLAVE); or i2cPort = open("/i2c/0",I2C_MASTER); • I2C device channel: /i2c/0 • I2C device mode: I2C_MASTER, or I2C_SLAVE. NetSilicon & Digi Confidential

11. Device close() • Calls i2c_dev_close() • Closes the I2C channel. • Example: ret = close(fd); NetSilicon & Digi Confidential

12. Device Read() • Calls i2c_dev_read(). • int i2c_dev_read(int channel, void * i2cMsg, int notUsed, int * notUsed1); Note: i2cMsg is pointer to the i2cMsg type. • The i2cMeg will be returned by a read callback function in an ISR. DO NOT access it before it is returned. NetSilicon & Digi Confidential

13. Device Write() • Calls i2c_dev_write(). • int i2c_dev_write(int channel, void * i2cMsg, int notUsed, int * notUsed1) • The i2cMsg will be returned by a write callback function in an ISR context. • DO NOT access the message before it is returned. NetSilicon & Digi Confidential

14. Device Ioctl() • Calls i2c_dev_ioctl() • Important flags: • I2C_SET_READ_CALLBACK_FUNC • I2C_SET_WRITE_CALLBACK_FUNC • I2C_SET_CLOCK_SPEED • I2C_SET_GCA_IRQ_ENABLE • I2C_FLUSH_BUFFER NetSilicon & Digi Confidential

15. Other APIs • void MCI2cBuildMsg(MC_I2C_MESSAGE_TYPE* i2cMsg, char* buf, unsigned long bufLength, unsigned char addr); NetSilicon & Digi Confidential

16. I2C Specific…. • I2C driver is interrupt driven and the I2C interrupt is part of the BBUS interrupt. After we install the I2C interrupt function, on receiving every data byte and I2C commannd, we will receive an interrupt generated by the I2C IP. The MCI2cInterrupt() function will then be called by the ISR handler. Based on the state of the current I2C bus and whether the Mercury is acting as an I2C Master or Slave, the appropriate function will be called. Please refer to the I2C Master or Slave State machine for ISR handling details. • A semaphore is used to keep multiple I2C port from opening at the same time. • A Event flag is created in the application example; but it is up to the application to decide whether to use it or not. The same applies to the Event flag in the nausbdevapp example as well. NetSilicon & Digi Confidential

17. Example • Typical User application A typical open function call is fd = open(“i2c/0”, I2C_MASTER); Or fd = open(“i2c/0”, I2C_SLAVE); A typical close function call is Ret = close(fd); NetSilicon & Digi Confidential

18. Read() Example • Typical usage: The third parameter is ignored. • Ret=Read(fd, i2cMsg, 0x0); • If (ret == -1) printf(“ read failed.\n”); NetSilicon & Digi Confidential

19. Write() example • Typical usage: The third parameter is ignored. • Ret=write(fd, i2cMsg, 0x0); • If (ret == -1) printf(“ write failed.\n”); NetSilicon & Digi Confidential

20. I2C message defination • typedef struct _MESSAGE_TYPE { char * buffer; unsigned short address; unsigned long bufLength; /* size of the buffer */ unsigned long availableDataLen; MC_I2C_BUFFER_STATE state; } MC_I2C_MESSAGE_TYPE; NetSilicon & Digi Confidential

21. Typical write Callback function • void writeCallBackFunc(MC_I2C_MESSAGE_TYPE * ptrData) { if (ptrData->state != I2C_INIT) { tx_event_flags_set(&i2cEvent,I2C_WRITE_EVENT_FLAG, TX_OR); /* free(ptrData); */ } return; } NetSilicon & Digi Confidential

22. Typical read callback function • void readCallBackFunc(MC_I2C_MESSAGE_TYPE * ptrData) { if (ptrData->state != I2C_INIT) { tx_event_flags_set(&i2cEvent,I2C_READ_EVENT_FLAG, TX_OR); /* free(ptrData); */ } return; } NetSilicon & Digi Confidential

23. Example application MCI2cBuildMsg(i2cMsg, ptrTemp, 26, 0x60); ret = write(i2cPort, i2cMsg, 0); MCInstallIsr (I2C_INTERRUPT, (MC_ISR_HANDLER) MCI2cInterrupt, (void *) 0, 0); while( 1 /* mySleepCount < 6 */) { ret = tx_event_flags_get(&i2cEvent, I2C_WRITE_EVENT_FLAG|I2C_READ_EVENT_FLAG, TX_OR_CLEAR, &actualEvent, TX_WAIT_FOREVER); …… NetSilicon & Digi Confidential

24. Important files • Driver: Src/bsp/devices/i2c/* • Example: Src/examples/nai2capp/itc_test.c NetSilicon & Digi Confidential