TL16C754B: Once FIFO enabled, it will loss data while sending data out?

Hi man,

I am using TL16c754b as uarts expantion. When FIFO is disabled, interrupt enabled,by polling LSR bit 5 or bit 6 till to HIGH and send the next data,it works well. However, when FIFO is enabled, wait untill by polling LSR bit 5 or bit 6 to High and send the next data,will loss data? for example, i send ascii char from '0' to '9' out and I will not receive '0' or '1' or '5',etc.Why?

Hardware info, DSP 6713 as controller.emif ce3 configured as async 8 width.

Software cods as follows(partial).

int UART_SENDBYTE(unsigned int port,unsigned char data)
{
 volatile unsigned char statustmp=0;
volatile unsigned char tmpst=0x0;
volatile unsigned char tmp=0x0,tmp1,tmp2;
volatile unsigned int lsr_falt;
 lsr_falt= *(unsigned int *)(0xb0000004);
 tmp1=*(unsigned char *)(BASE_UART + (port <<(20-2)) + 0x4);
 tmp2=*(unsigned char *)(BASE_UART + (port <<(20-2)) + 0x5);

 statustmp=*(volatile unsigned char *)(BASE_UART + (port <<(20-2)) + UART_LSR);//
 tmpst= (statustmp&(1<<LSR_TRANSMIT_AND_SHIFT_EMPTY));//
 //tmpst= (statustmp&(1<<LSR_TRANSMIT_EMPTY));
 if(tmpst)//if empty then send
 {
  *(volatile unsigned char *)(BASE_UART + (port <<(20-2))+UART_THR) = data;
  return(SENDOK);  
 }
 else
 {
  lsr_falt= *(unsigned int *)(0xb0000004);
   tmp1=*(unsigned char *)(BASE_UART + (port <<(20-2)) + 0x4);
 tmp2=*(unsigned char *)(BASE_UART + (port <<(20-2)) + 0x5);
  return(SENDERROR);
 }
}

int uart_send_byte_while(unsigned int port,unsigned char data)
{
 while(UART_SENDBYTE(port,data)!= SENDOK);
}

main()

{

for(i=0;i<1000;i++)
   for(k='0';k<='9';k++)
   {
   uart_send_byte_while(UART1,k);
   
   }

}

//////////////////////

some question here,

1, DSP works in freq 200M,should it too fast? but I try to delay between two sends,not works

2,can you give me a reference code for test?

3,when in FIFO mode, once LSR bit 5 is 1, then I send just only one data to THR, is it ok? or Should I send till the FIFO is full?

4,I initialized the 16C754 as follows, first I reset the 16c754 by pull high the RESET ,then set the baud rate, then the MCR ,FCR, IER,LCR ,is this ok?

5,

thanks for the detailed explanation. This helps a lot.

Regards,

Praveen GD