SPRZ423K October   2014  – May 2024 TMS320F28075 , TMS320F28075-Q1 , TMS320F28076

 

  1.   1
  2.   Abstract
  3. 1Usage Notes and Advisories Matrices
    1. 1.1 Usage Notes Matrix
    2. 1.2 Advisories Matrix
  4. 2Nomenclature, Package Symbolization, and Revision Identification
    1. 2.1 Device and Development Support Tool Nomenclature
    2. 2.2 Devices Supported
    3. 2.3 Package Symbolization and Revision Identification
  5. 3Silicon Revision C Usage Notes and Advisories
    1. 3.1 Silicon Revision C Usage Notes
      1. 3.1.1 PIE: Spurious Nested Interrupt After Back-to-Back PIEACK Write and Manual CPU Interrupt Mask Clear
      2. 3.1.2 Caution While Using Nested Interrupts
      3. 3.1.3 SYS/BIOS: Version Implemented in Device ROM is not Maintained
      4. 3.1.4 SDFM: Use Caution While Using SDFM Under Noisy Conditions
      5. 3.1.5 McBSP: XRDY Bit can Hold the Not-Ready Status (0) if New Data is Written to the DX1 Register Without Verifying if the XRDY Bit is in its Ready State (1)
    2. 3.2 Silicon Revision C Advisories
      1.      Advisory
      2.      Advisory
      3.      Advisory
      4.      Advisory
      5.      Advisory
      6.      Advisory
      7.      Advisory
      8.      Advisory
      9.      Advisory
      10.      Advisory
      11.      Advisory
      12.      Advisory
      13.      Advisory
      14.      Advisory
      15.      Advisory
      16.      Advisory
      17.      Advisory
      18.      Advisory
      19.      Advisory
      20.      Advisory
      21.      Advisory
      22.      Advisory
      23.      Advisory
      24.      Advisory
      25.      Advisory
      26.      Advisory
      27.      Advisory
      28.      Advisory
      29.      Advisory
      30.      Advisory
      31.      Advisory
      32.      Advisory
      33.      Advisory
      34.      Advisory
      35.      Advisory
      36.      Advisory
  6. 4Silicon Revision B Usage Notes and Advisories
    1. 4.1 Silicon Revision B Usage Notes
    2. 4.2 Silicon Revision B Advisories
      1.      Advisory
      2.      Advisory
      3.      Advisory
      4.      Advisory
      5.      Advisory
      6.      Advisory
      7.      Advisory
      8.      Advisory
      9.      Advisory
  7. 5Documentation Support
  8. 6Trademarks
  9. 7Revision History

Advisory

HWBIST: Avoiding Spurious Interrupts While Using HWBIST

Revisions Affected

B, C

Details

HWBIST has the capability to log interrupts received while the CPU is under test and reissue them after HWBIST completes. Interrupts received in the clock cycle before the interrupt logging is enabled are executed before the HWBIST runs. In the next cycle, when interrupt logging is enabled, interrupts are logged and reissued when the HWBIST completes.

The interrupt events for CPU Timer 1 and CPU Timer 2 are valid for 2 SYSCLK cycles. If the first cycle happens a cycle before interrupt logging is enabled and the second cycle coincides with the enabling of interrupt logging, the interrupt is executed once as expected before the logging (clearing the CPU Timer TCR.TIF flag), but then is logged by the interrupt logger and triggered again after HWBIST completes. Because the TCR.TIF flag was already cleared by the previous ISR, this is an unexpected spurious interrupt.

This is only applicable to the non-PIE CPU Timer interrupts. The CPU Timer 0 interrupt is managed by the PIE and its pulse width is only one SYSCLK cycle.

Workarounds

Disable CPU Timer 1 and 2 interrupts before enabling interrupt logging and restore them later. The steps are:

  1. Clear the timer interrupt enable bit TCR.TIE for CPU Timers 1 and 2.
  2. Run normal HWBIST sequence: save registers, enable interrupt logging, run HWBIST, restore registers, end interrupt logging.
  3. Check if the CPU Timers' TCR.TIF flags are set. If the flags are set, set the corresponding CPU IFR bit to trigger the interrupt.
  4. Restore TCR.TIE.