Thanks for replays, but I'm totally new in c51 and luck of asm experience. So I prefer easy UART0 "C" example, how to use uart with internal baud rate generator:

void main (void) 
{
	   SCON = 0x50;		/* uart in mode 1 (8 bit), REN=1 */
	   BDRCON &=0xEC;		/* BRR=0; SRC=0; */
	   BDRCON |=0x0C;		/* TBCK=1;RBCK=1; SPD=0 */
	   BRL=0xFD;		/* 9600 Bds at 11.059MHz */
	 	ES = 1;		/* Enable serial interrupt	*/
		EA = 1;		/* Enable global interrupt */
	   BDRCON |=0x10;		/* Baud rate generator run*/
   while(1);
}		


void serial_IT(void) interrupt 4 
{...}

void serial_IT(void) interrupt 10 
{...}


 

Is the 2nd uart require another baud source ? and additionally I should run 2-nd uart by adding smth like this:

Tha problem of Keil is that it has not true header description (like this): http://www.keil.com/dd/chip/3986.htm 

There it was told to use "at89c51xd2.h" for AT89C51RE2, but I can't find there BDRCON_1 register (for ex, 0xBCh in PDF, snd uart) and some other. Anyway, I have most newest v4.22 of Keil.