Honored Contributor
Honored ContributorIf i understand you right you have the following setup :
I guess you use half duplex like RS485 ? You disable the receiver during transmitting, in order not to receive your own data, and reenable the receiver afterwards again ? We use the RTS signal to control a RS485 driver. Mostly the first received character is wrong. But sometimes a byte in the middle is wrong. A 0x02 is always a 0x04 if we get a wrong data from the UART. What i do not understand from your reply is "if we plug in another device" does this mean you connect another device to your cable ? does this have an effect of the serial datastream ? Here we can plug and unplug the serial datastream is not affected but sometimes the UART delivers wrong data. Note that only the nios Uart delivers wrong data. "real" Uarts like a 16450 or 16550 always receive the correct value if nios delivers the wrong value. A Digital scope (HP54645D) with a snapshot of the receiver in pin of the uart *always* shows the correct value. The same HW setup without the nios sopc uart, but instead used an own core, is able to comunicate up to 16MBit/sec without any change in the HW setup except the FPGA. Regards. Michael Schmitt
