Similar to what has been seen on the Stellaris® family of devices, Concerto™ offers two independent I²C modules. The I²C bus provides bi-directional data transfer through a two-wire design which is a serial data line, SDA, and a serial clock line, SCL. Each I²C module supports both sending and receiving data as either a master or a slave and can operate simultaneously as both the master and slave. There are a total of four I²C modes that are supported which are master transmit, master receive, slave transmit, and slave receive. Both of the I²C master and slaves can generate interrupts. The master generates interrupts when a transmitter receive operation either completes or aborts and the slave will generate interrupts when data has been sent or requested by a master. The I²C modules can be placed into an internal loopback mode for diagnostics or debug work. Also note that the I²C modules are accessible from the M3 core only, µDMA access is not possible.