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- I2C Addressed As a Slave (IAAS) problem
I2C Addressed As a Slave (IAAS) problem
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I2C Addressed As a Slave (IAAS) problem
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Hello,
I am using two QE64 MCUs to communication with each other through I2C using the 10-bit addressing mode.
The slave generates an IAAS interrupt (the only interrupt) even if the master sends to an address different than the address configured in the slave. However, the master does effectively generate a No ACK interrupt because the slave does not answer and does not acknowledge (even if it generates the IAAS interrupt!).
Has anyone seen such a behavior before? Is this normal I2C behavior?
Thank you!
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With further investigation, it seems that the IAAS interrupt occurs because the 2 MSBs of the 10-bit slave address are the same for both slaves connected on the bus. Hence, the first byte transmitted by the master is received and acknowledged by all slaves having the same 2 MSBs as transmitted by the master, causing the IAAS interrupt to occur for both slaves..it seems. Thankfully, only the slave with the address matching the second address byte (the remaining 8 bits of address) sent by the master responds with the 2nd ACK and the transaction continues as normal.
This behavior is not describe in the QE128 Reference Manual. And yes, I RTFM for those of you who wonder.
Any chance of someone experiencing the same problem/behavior?
