i2c receiving problem?

[aravindpb5009]

hai 

        I have  one doubt i am  using lpc824 mcuxpresso Ide. i need to receive the i2c o/p in salve side my slave is ads 1115  i set my controller clk freq is 12mhz , and i2c freq is 30mhz baud rate is 400 khz   its ok for receiving the data from the receiver side, because why i am asking means my controller frq is lesser than slave freq let me know the solution 

Thanks&regards 

Aravind P

[xiangjun_rong]

Hi, Aravind palanisamy,

As you know that the ads1115 is an I2C slave device, the LPC824 is the master, the SCL clock frequency is determined by only the I2C module of LPC824.

Regarding your question that "my controller frq is lesser than slave freq", as the following section copied from DS of ads1115, we can see that the fscl is from 10K to 400KHz in fast mode, from 10K to 3.4MHz in high speed mode, I think the I2C of LPC824 can get the frequency the SCL clock required.

For example, the Peripheral clock PCLK is 30MHz, if you set the I2C Clock Divider register as 75, the SCL clock frequency is about 400KHz, you can increase the valuer to get scl clock frequency less than 400KHz.

Hope it can help you

BR

XiangJun Rong