• State TI Thinks Resolved
  • Locked Locked
  • Replies 1 reply
  • Answers 1 answer
  • Subscribers 30 subscribers
  • Views 317 views
  • Users 0 members are here
Support feedback
Options
Options
Related

This thread has been locked.

If you have a related question, please click the "Ask a related question" button in the top right corner. The newly created question will be automatically linked to this question.

Original question:

CCS/EK-TM4C1294XL: TM4C1294 UART issue

EK-TM4C1294XL: How to set UART's MSB in TM4C1294

Guo Yinxiu
Prodigy 170 points
Part Number: EK-TM4C1294XL

Hello, 

      I found UART is in LSB mode in TM4C1294(The data I see on the oscilloscope is the opposite of the data bit I sent.), which makes the received characters are garbled.

     How will I do to output the correct characters? Thank you.

  • 0
    TI__Guru**** 191886 points

    Hi,

      The TM4C129 MCU UART only transmits in LSB first and this is the standard protocol. Please see below datasheet description as well as general UART protocol description from Wikipedia. All transmitters and receives must follow the same protocol. 

    16.3.1 Transmit/Receive Logic
    The transmit logic performs parallel-to-serial conversion on the data read from the transmit FIFO.
    The control logic outputs the serial bit stream beginning with a start bit and followed by the data bits
    (LSB first), parity bit, and the stop bits according to the programmed configuration in the control
    registers. See Figure 16-2 on page 1165 for details.
    The receive logic performs serial-to-parallel conversion on the received bit stream after a valid start
    pulse has been detected. Overrun, parity, frame error checking, and line-break detection are also
    performed, and their status accompanies the data that is written to the receive FIFO.