In August 2025, delivered a targeted capability for the TI IUAe Nuttx repository to improve serial interface reliability on the XMC4 by making USIC FIFO buffer sizes configurable for unused channels. The change specifically enables control of FIFO buffer offsets when CHAN0 is not UART but CHAN1 is, allowing precise TX/RX buffer management for the active channel. Implemented as a fix in arch/xmc4 to ensure full user control over USIC FIFO buffers even when CHAN0 is disabled. This work is captured in commit 8fea354a0f8f85060d9f90dec7947bf68df6ae07, titled arch/xmc4 : fix serial buffer size for unused channel. Business value includes reduced misconfiguration risk, improved throughput stability, and greater flexibility for XMC4-based designs, contributing to faster time-to-value and lower support overhead.