SLAU847D October 2022 – May 2024 MSPM0L1105 , MSPM0L1106 , MSPM0L1227 , MSPM0L1228 , MSPM0L1228-Q1 , MSPM0L1303 , MSPM0L1304 , MSPM0L1304-Q1 , MSPM0L1305 , MSPM0L1305-Q1 , MSPM0L1306 , MSPM0L1306-Q1 , MSPM0L1343 , MSPM0L1344 , MSPM0L1345 , MSPM0L1346 , MSPM0L2227 , MSPM0L2228 , MSPM0L2228-Q1
Digital filter
Digital filter is based on the UART functional clock. The DGFSEL bits in the UARTx.GFCTL register can be programmed to provide glitch suppression on the RX line and assure proper signal values. The glitch suppression value is in terms of functional clocks. All signals are delayed internally when glitch suppression is nonzero. For example, if DGFSEL is set to 0x5, 5 clocks should be added onto the calculation for the expected transaction time. The DGFSEL need to be configured for the glitch suppression pulse width to be shorter than 1/3 of a normal data pulse, to avoid a normal pulse is filtered unexpectedly.
Analog filter
The analog glitch suppression on the RX line is based on the analog glitch filter and it can be selected with the AGFSEL bits in the UARTx.GFCTL register. See data sheet for the select-able glitch filter values. The analog glitch filter is enabled with the AGFEN, if not set the input signals will be passed through to the UART module without filtering.