Question: Is there any error in transmission speed introduced by the PSoC I2C Slaves?
The transmission speed is dependent on the I2C Master because the Master generates the clock for the communication. So there is no error in transmission speed introduced by the PSoC Slaves. But the I2C Slave stalls the SCL line before sending the ACK or NAK on each byte. The duration of the stall will depend on the CPU speed at which the PSoC is operating. This will affect the overall data transfer rate.