Problem with serial interruption

Greetings.

I’m working with the RCM5700 device.
I’m using the serial ports C and D.

Some time ago I had problems with the serial port interrupts. The problem was the same interrupt occurs for reception and transmission.

I troubleshoot the problem as follows:

root interrupt void serialC_isr()
{
auto int int_serC;
int_serC = RdPortI(SCSR);//clear interruption
if (BitRdPortI(SCSR,7)==1) is it reception?
{
… my code here if the interruption is reception
}
else if (BitRdPortI(int_serC,3) == 1)
{
#asm
ioi ld (SCSR), a;
#endasm
}
#asm
ioi ld (SCSR), a;
#endasm
}

Now I’m using the serial port B and I have the same problem: when I transmit something, interrupt of reception occurs.

How can solve this problem?

Fabián