Credit Card Numbers - Visa. These Credit card numbers validate for Visa credit cards. The number and information is as real as it can be, and contains valid bin information. The structure of the credit card number starts with a valid bin number and also validates against the LUHN's formula.
UART is a protocol (Universal asynchronous receiver/transmitter ) for serial transfer of information. You ask about an embedded system with mentioning which so I'll assume that you have a block diagram with one indicating UART.
One of the seven tools of quality, a flowchart shows how the entire system functions, and where error and wastes occur. This information is used in defining, documenting, studying, and improving the system. Also called flow diagram, flow process chart, or network diagram.