Do you mean I shall launch a 1 bit delay in the interrupt routine after the TI occurs to have a second stop ?

If the format is 8 bits + parity + 2 stop bits, all that means is 9 bit mode and "wait a bit between characters".

In most cases, you would have mov SBUF,... on the TI interrupt. If 9 bits + 2 stops is required then in TI start a timer of 1 bit time and do the mov SBUF,... in the timer interrupt.

Erik