Re: trouble with S12XS SCI controller

thanks for ur help.I guess i've catched a wrong address of the SCICR2 when trying to disable Tx interrupt in the ISR before exiting it.

Now it is working.but i am having another situation,i am using a service PUT_Byte_Exe which puts a byte in Tx Buffer(circular buff)
then enables TDRE Flag INT request so as the interruption could directly handle sending this Byte.but what if i'm exiting the ISR and calling this service again ?? i've found that data will be overwritten cause when enabling Tx Interrupt(TIE = 1) TDRE will be set to 1 regardless of previous data has been already sent or not.