I had a working design in designer 4.4 for the cy21434 using ezi2c. when i imported the design to designer 5.0 and recompiled, I had to move the relocatable code start address to 0x155. I assume this is due to newer versions of the csd code etc. When I run the code it all seems to work as before except the I2C NAKS when the PSOC is being written to. The slave address is correct because it can be read from just fine. Is there a possibility the data structure associated with the I2C go moved to some place it can't be written to? Not sure where to go from here.