A UART or Universal Asynchronous Receiver / Transmitter is a longstanding method of communications in electronics. UART is also sometimes refered to as a serial port or COM port since it has been supported in personal computers for decades under this name. UART is also the basic communication layer for serial interfaces like RS-232. In a general sense, a UART is a form of serial communication that breaks down a byte (8 bits) into a series of 1’s and 0’s driven across a wire. The UART is asynchronous meaning that it is not accompanied by a clock but rather a scheme for synchronizing the transmitter clock with the receiver clock using a coding scheme to recover the clocking information. Typically a UART utilizes a “start bit” to deliver this clocking or synchronization information. The start bit is then followed by a series of 5-8 data bits and a stop bit. The speed at which a UART operates is known as the Baud rate. The number of bits and baud rate are preconfigured and assumed to be known by both the transmitter and the receiver. A UART may also include a parity bit. UARTs are still used in electronics today due to their simplicity and easy interface with computers, they are sometimes replaced with a synchronous interface such as SPI or IIC which can operate more robustly at faster datarates.
Triad designs many ASICs with UART interface both for use in debugging as well as normal operation. Our Via-Configurable logic tiles are a convenient place to implement UART logic to interface an ASIC to a multitude of other components. Triad’s engineers and Mixed Signal Integration Architechts can work with you to select the right communication interface(s) for your ASIC design.