FAQ

FAQ

When the RLS (Receive Line Status) interrupt occurs during UART data transmission, how to handle PEF, FEF and BIF flags that may cause interrupt?  Issue Date:2016-07-01

Since the three flags are saved with UART data in the FIFO, these flags must be cleared by writing 1 to them before the data is read out. This can avoid FIFO level changes, causing the PEF, FEF and BIF saved in the upper layer of FIFO unable to be cleared.
If the data has been read out but the three flags are not cleared, these flags will remain in the FIFO. The next time the same level FIFO data is read out, the RLS interrupt may inadvertently occur due to these old flags.

Products: Microcontrollers ,Arm Cortex-M0 MCUs ,M051 Base Series ,M0518 Series ,M0519 Series ,Mini51 Base Series ,Nano100/102 Base Series ,Nano110/112 LCD Series ,Nano120 USB Series ,Nano130 Advanced Series ,NUC029 Series ,NUC100/200 Advanced Series ,NUC120/122/123/220 USB Series ,NUC130/230 CAN Series ,NUC131/NUC1311 CAN Series ,NUC140/240 Connectivity Series ,Arm Cortex-M4 MCUs ,M451 Base Series ,M451M Series ,M452 USB Series ,M453 CAN Series ,M4TK Touch Key Series ,NUC442/472 Series ,NUC505 Series
Applications:
Function: Peripherals,Connectivity,UART