The D16450 is a soft Core of a Universal Asynchronous Receiver/Transmitter (UART) functionally identical to the TL16C450. D16450 performs serial-to-parallel conversion on data characters received from a peripheral device or a MODEM, and parallel-to-serial conversion on data characters received from the CPU. The CPU can read the complete status of the UART at any time during the functional operation. Status information reported includes the type and condition of the transfer operations being performed by the UART, as well as any error conditions (parity, overrun, framing, or break interrupt). D16450 includes a programmable baud rate generator that is capable of dividing the timing reference clock input by divisors of 1 to (216-1), and producing a 16 × clock for driving the internal transmitter logic. Provisions are also included to use this 16 × clock to drive the receiver logic. The D16450 has complete MODEM control capability, and a processor-interrupt system. Interrupts can be programmed to the user's requirements, minimizing the computing required to handle the communications link.
The separate BAUD CLK line allows to set an exact transmission speed, while the UART internal logic is clocked with the CPU frequency.
The core is perfect for applications, where the UART Core and microcontroller are clocked by the same clock signal and are implemented inside the same ASIC or FPGA chip, as well as for standalone implementation, where several UARTs are required to be implemented inside a single chip, and driven by some off-chip devices. Thanks to universal interface D16450 core implementation and verification are very simply, by eliminating a number of clock trees in complete system.