Restart Condition

A Restart condition is valid any time that a Stop is valid. A host can issue a Restart if it wishes to hold the bus after terminating the current transfer. A Restart has the same effect on the client that a Start would, resetting all client logic and preparing it to clock in an address. The host may want to address the same or another client. Figure 1 shows the waveform for a Restart condition.

In 10-bit Addressing Client mode, a Restart is required for the host to clock data out of the addressed client. Once a client has been fully addressed, matching both high and low address bytes, the host can issue a Restart and the high address byte with the WR/ bit set. The client logic will then hold the clock and prepare to clock out data.
Figure 1. I2C Restart Condition