how to reduce the delay of i2c

[jeffgu]

Hello,

I'm using the i2c to read data from device. Presently it is OK to read the data correctly. See the attached waveform:

yellow line: i2c SCL

green line:  i2c SDA

This figure indicates a 10bytes data read, SCL frq=300KHz

In thewaveform, there are 2 long delay during i2c access. The first delay happens between address and first data read, the second delay happens between i2c Nack and i2c Stop. Is there any way to shorten or eliminate these 2 delays?

For a easy understanding, the source code for i2c reading is like:

i2c_Start();     i2c_write_byte(W9002_ADDRESS<<1|I2C_READ);     i2c_Wait();     i2c_EnterRxMode();     i2c_read_byte(dst[0]);   //Dummy read     i2c_Wait();     for(i=0;i<8;i++){         i2c_read_byte(dst[i]);         i2c_Wait();           }     i2c_DisableAck();     i2c_read_byte(dst[i++]); i2c_Wait();     i2c_Stop();     i2c_read_byte(dst[i]);

[jeffgu]

Anyone who can help me?

[Jorge_Gonzalez · Accepted solution]

Hello jeff gu:

Those delays can actually be caused by your I2C slave holding the clock line. Can you try with a different slave? Or even without a slave?

Regards!,
Jorge Gonzalez

-----------------------------------------------------------------------------------------------------------------------
Note: If this post answers your question, please click the Correct Answer button. Thank you!
-----------------------------------------------------------------------------------------------------------------------

[jeffgu]

Jorge,

Thank you so much for your answer. I tried it without i2c slave, the result is exactly as you said. The delay should be caused by the slave device.

I would like to put the empty slave waveform here for a easy understanding to everyone.