uart lattice Universal Asynchronous Receiver

The Universal Asynchronous Receiver Transmitter (UART) is a popular and widely-used device for data communication in the field of telecommunication. There are different versions of UARTs in the industry. Some of them contain FIFOs for the receiver/transmitter data buffering and some of them have the 9 Data bits mode (Start bit + 9 Data bits + Parity + Stop bits). This application note describes a fully configurable UART optimized for and implemented in a variety of Lattice devices, which have superior performance and architecture compared to existing semiconductor ASSPs (application-specific standard products).
This UART reference design contains a receiver and a transmitter. The receiver performs serial-to-parallel conversion on the asynchronous data frame received from the serial data input SIN. The transmitter performs parallel-toserial conversion on the 8-bit data received from the CPU. In order to synchronize the asynchronous serial data and to insure the data integrity, Start, Parity and Stop bits are added to the serial data. An example of the UART frame format is shown in Figure 1 below.