SPRZ267J March   2009  – September 2020 TMS320C28341 , TMS320C28342 , TMS320C28343 , TMS320C28343-Q1 , TMS320C28344 , TMS320C28345 , TMS320C28346 , TMS320C28346-Q1

 

  1. 1Introduction
  2. 2Device and Development Support Tool Nomenclature
  3. 3Device Markings
  4. 4Usage Notes and Known Design Exceptions to Functional Specifications
    1. 4.1 Usage Notes
      1. 4.1.1 PIE: Spurious Nested Interrupt After Back-to-Back PIEACK Write and Manual CPU Interrupt Mask Clear
      2. 4.1.2 Caution While Using Nested Interrupts
    2. 4.2 Known Design Exceptions to Functional Specifications
      1.      Advisory
      2.      Advisory
      3.      Advisory
      4.      Advisory
      5.      Advisory
      6.      Advisory
      7.      Advisory
      8.      Advisory
      9.      Advisory
      10.      Advisory
      11.      Advisory
      12.      Advisory
  5. 5Documentation Support
  6. 6Trademarks
    1.     Revision History

Advisory

SCI: Incorrect Operation of SCI in Address Bit Mode

Revision(s) Affected

0

Details

SCI does not look for STOP bit after the ADDR bit. Instead, SCI starts looking for the start bit beginning on sub-sample 6 of the ADDR bit. Slow rise-time from ADDR to STOP bit can cause the false START bit to occur since the 4th sub-sample for the start bit may be sensed low.

GUID-3C55BB32-4C9B-45B9-AD6B-A272A902EFBD-low.gifFigure 4-1 Difference Between Expected and Erroneous Operation of START Bit

Workaround(s)

Program the baud rate of the SCI to be slightly slower than the actual. This will cause the 4th sub-sample of the false START bit to be delayed in time, and therefore occur more towards the middle of the STOP bit (away from the signal transition region). The amount of baud slowing needed depends on the rise-time of the signal in the system. Alternatively, IDLE mode of the SCI module may be used, if applicable.