I am using serial port1 on the Infineon 80c517a. I am using Keil C51 v6.21. I have initialized it as follows:

void Serial1Init (void)
{
EAL = 0; //global disable
IEN2 &= 0xFE; //ES1: disable serial 1 interrupts

S1RELL=0xE8; //sets the baud rate to 19200bps S1RELH=0x03;

S1CON &= 0x00;
S1CON |=0x90; //sets SM=1,SM21=0,REN1=1 10010000

EAL = 1; //global enable
IEN2 |= 0x01; //ES1: enable serial 1 interrupts
}

The wierd thing is that when I load a value into S1BUF directly using a for loop from my main function I can see the output on the serial window; however, when I run my program (using a circular buffer) I see the values being loaded into S1BUF, but I see nothing on the serial window.

Any ideas??