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Altera_Forum's avatar
Altera_Forum
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16 years ago

Bug in serial port com

When transferring (using Hyperterminal) 2 identical characters, the second character may get its MSB flipped. For example, sending "FF" may be received as "0x46 0xC6".

Has anybody seen this and know of a solution?

I'm using Stratix ver of NIOS board.

Thanks.

2 Replies

  • Altera_Forum's avatar
    Altera_Forum
    Icon for Honored Contributor rankHonored Contributor
    16 years ago

    There is a problem with your design.. I often working with standard UART and Fifoed_UART and there is no such problem for me more than 4 years..

  • Altera_Forum's avatar
    Altera_Forum
    Icon for Honored Contributor rankHonored Contributor
    16 years ago

    It might be that you baud rate is slightly out, and that the wrong bit gets sampled - in theory this should generate a receive framing error, but those aren't always reported to apps.

    The byte will be sent LSB first, so you should be able to work out what is being mis-sampled. Remember the async byte pattern is 10 bits long (a zero before the byte and a one after it).