Since the BCC buffers each I²C data byte and regenerates the I²C protocol on the remote side of the link, the overall I²C throughput will be reduced. The reduction is dependent on the operating frequencies of the local and remote interfaces. The local I²C rate is based on the host controller clock rate, while the remote rate depends on the settings for the proxy I²C controller (SCL frequency).

For purposes of understanding the effects of the BCC on data throughput from a host controller to a remote I²C controller, the approximate bit rate including latency timings across the control channel can be calculated by the following:

9 bits / ((Host_bit * 9) + (Remote_bit * 9) + FCdelay + BCCdelay)

Example of DS90UB953/954 chipset:

For the 100 kbit/s (100 kHz) :

Host_bit = 10us (100 kHz)

Remote_bit = 13.5us (default 74 kHz)

FCdelay = 225ns (typical value)

BCCdelay = 1.5us (typical value for 50 Mbps back channel rate)

Effective rate = 9bits / (90us + 121us + 0.225us + 1.5us) = 42.3 kbit/s

Since the I²C protocol includes overhead for sending address information as well as START and STOP bits, the actual data throughput depends on the size and type of transactions used. Use of large bursts to read and write data will result in higher data transfer rates.