The TL16C750 is a functional upgrade of the TL16C550C asynchronous communications element (ACE), which in turn is a functional upgrade of the TL16C450. Functionally equivalent to the TL16C450 on power up (character or TL16C450 mode), the TL16C750, like the TL16C550C, can be placed in an alternate mode (FIFO mode). This relieves the CPU of excessive software overhead by buffering received and transmitted characters. The receiver and transmitter FIFOs store up to 64 bytes including three additional bits of error status per byte for the receiver FIFO. The user can choose between a 16-byte FIFO mode or an extended 64-byte FIFO mode. In the FIFO mode, there is a selectable autoflow control feature that can significantly reduce software overload and increase system efficiency by automatically controlling serial data flow through the RTS output and the CTS input signals (see Figure 1).