29.4.9 Restart Condition

A Restart is valid any time that a Stop is valid. A host can issue a Restart if it intends to hold the bus after terminating the current transfer. A Restart has the same effect on the client that a Start has, resetting all client logic and preparing it to clock in an address. The host may want to address the same or another client. Figure 29-13 shows the wave form 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 R/W bit set. The client logic will then hold the clock and prepare to clock out data.

After a full match with R/W clear in 10-bit mode, a prior Match flag is set and maintained until a Stop condition, a high address with R/W clear, or high address match fails.

Figure 29-13. I2C Restart Condition