TMS320F28069F: InstaSPIN Projects and Labs : Lab10a (Overmodulation) and Lab10c (Lab10a with fpu32).

Hello,

I have a question on the InstaSPIN Projects and Labs.

Specifically it is on Lab10a (Overmodulation) and Lab10c (Lab10a with fpu32).

I have found out that the mainISR() has some difference between Lab10a and Lab10c.

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1. The code snippets in mainISR() of Lab10a are as follows:

  if(measurableShuntThisCycle > two_phase_measurable)
  {
      gAdcData.I.value[0] = gIavg.value[0];
      gAdcData.I.value[1] = gIavg.value[1];
      gAdcData.I.value[2] = gIavg.value[2];
  }

My analyses for this code snippet are as follows:

(1) The variable of measurableShuntThisCycle has the data type of enumeration. The constant of two_phase_measurable is equal to 2 while all_phase_measurable is equal to 1.

(2) Therefore the above-listed code snippet may not be executed most of times unless overmodulation is activated for high load current. Here my PCB has the configuration of three low-side shunt current measurement.

2.  Meanwhile the code snippets in mainISR() of Lab10c are as follows:

  if(ignoreShuntThisCycle > use_all)
  {
      gAdcData.I.value[0] = gIavg.value[0];
      gAdcData.I.value[1] = gIavg.value[1];
      gAdcData.I.value[2] = gIavg.value[2];
  }

My analyses for this code snippet are as follows:

(1) The variable of ignoreShuntThisCycle has the data type of enumeration. The constant of  use_all is equal to 0.

(2) Therefore the above-listed code snippet is always executed.

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Please comment on my analyses for these code snippets.

Why do Lab10a and Lab10c use the different mainISR() function in association with the above-listed code snippets?

Thank you for your guidance.

With regards,

JS Yoo