March 25, 2010: Can some please address this question for my customer: Thank you. Ray Franzen (Infinity Sales: TI Rep)
We have 2 beagleboards connected together via UART 0 and UART 1 (UART 2 is dedicated to the console) on the expansion headers. We send data back and forth across the ports simultaneously. We have only the THR_IT interrupt enabled to signal that a UART message has gone out (IER). In the interrupt handler we check to see if the interrupt is indeed a THR interrupt by looking at the IIR register. We notice though that many times we get a spurious interrupt since the IIR register is showing 0xc1 (which the TI documentation indicates is a modem interrupt). Since IER is set to 2 we did not expect this interrupt to come in on this interrupt line. Do you have any ideas what might be causing this? We see this interrupt (albeit less often) when we transmit and receive on only UART 0. BTW we have set the MUX for these pins for no pull up or pull down. Is this correct? The data looks good (we have checksums on the messages), it's just that I am getting these spurious interrupt. Thanks in advance for looking at this.
<Service Request # 1-642002454>
