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Getting UART State always Idle even if RXD is LOW

Question asked by dharmendra gevariya on Apr 9, 2018
Latest reply on Apr 10, 2018 by Erwan Y

Hello Forums,


I am working on SPC570Sx 32-bit processor.

I facing the issue with the UART Idle line.


In our application software has to detect the wake up pattern for Diagnostic Tool(Fast Init).

we don't want to use the Auto Wakeup mode to detect the Wakeup signal So the Auto Wakeup mode is Disabled.


The idea is that when ever the RXD pin will goes low for certain  time period(about 25ms) we will consider as Wake up.


Software is checking the the LINSR register with field LINS values to detect the Idle state.In Microcontroller Manual LINS values in given like 0x1 Init,0x2 Idle,0x3 Sync Break,0x4 Sync Del and so on....


So When ever the RXD pin goes low, we are expecting the LINS values other than 0x2 (Idle state).

and we starts the timer for Wake up detection.


But I observed that LINs has always value 0x2 Idle even if the RXD pin goes low( Idle -> LOW).

I have checked the RXD pin status by using the register Uartsr with field RDI and its coming low.



please can someone  help me to resolve this issue ?