Hello, The following two patches add RX interrupt support for lm3s69xx UART. The patches were tested with QEMU and with LM3S3749 board. [PATCH 1/2] bsp/lm3s69xx: More access macros for UART data register [PATCH 2/2] bsp/lm3s69xx: Use interrupts for UART receive Regards, Eugeniy Meshcheryakov