I don't have the data sheet, but most likely you will have only one interrupt source. The interrupt service routine will need to check to see which channels have data and then extract the data for those channels and place in the right buffer list. There might even be a receive buffer (multiple bytes) for each channel that needs to be extracted.

Then there is an issue of transmitting data. You might have the option of pointing to a buffer of data to be transmitted, and it interrupts you when it is finished. But, this feature requires DMA which isn't supported on the 8051. There should be a way of loading multiple bytes for transmittion.

If you get a single interrupt for each data byte, there is no hope of dealing with 8 simultaneous channels unless using a slow baud rate (maybe 2400). But then there wouldn't be any time to do anything with the data.

What's this going to be used on?

<>< Lance.