UART Reference Design - WISHBONE Compatible

Universal Asynchronous Receiver/Transmitter Reference Design

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Reference Design LogoThe Lattice WISHBONE compatible UART (Universal Asynchronous Receiver/Transmitter) peripheral provides an interface between the WISHBONE system bus and an RS232 serial communication channel. 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-to serial 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. In FIFO mode, the RBR (Receiver Buffer Register) in the RXCVER block and the THR (Transmit Hold Register) in the TXMTT block become 16-word-deep FIFOs. In non-FIFO mode, these are simple registers.

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Block Diagram

UART (Universal Asynchronous Receiver/Transmitter) - WISHBONE Compatible Block Diagram

Performance and Size

Tested Devices* Language Performance I/O Pins Design Size Revision
LCMXO2-1200HC-4TG144CES Verilog >60MHz 52 274 LUTs 1.3
LCMXO2-1200HC-4TG144CES VHDL >60MHz 52 267 LUTs 1.3
LCMXO2280C-5T144C Verilog >60MHz 52 253 LUTs 1.3
LCMXO2280C-5T144C VHDL >60MHz 52 256 LUTs 1.3
LFXP2-5E-5TN144C Verilog >60MHz 52 323 LUTs 1.3
LFXP2-5E-5TN144C VHDL >60MHz 52 312 LUTs 1.3

* May work in other devices as well.

Note: The performance and design sizes shown above are estimates only. The actual results may vary depending upon the chosen parameters, timing constraints, and device implementation. See the design's documentation for details. All coding and design work was done on a PC platform unless noted otherwise.


Technical Resources
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RD1042 1.6 12/1/2014 ZIP 58.5 MB
WISHBONE UART - Documentation
FPGA-RD-02137 1.7 2/5/2021 PDF 1.1 MB

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