Hi,
I'm back on our TOF project after a hiatus of a year or so and am currently at a point where I need to understand the details of the register to properly configure the OPT9221. We have our own circuit design interfacing the OPT9221.
The question at this time is on the Sin and Cos coefficients for the Base and De-aliasing. The datasheet provides 2 formulas (Equation 19, page 32) to calculate these Sin and Cos coefficients. However the results don't match the default values.
Formulas :
| Base Frequency | 4 quads | 6 quads |
| Sin F1 Q0 Coeff | 0 | 0 |
| Sin F1 Q1 Coeff | 32767 | 28377 |
| Sin F1 Q2 Coeff | 0 | 28377 |
| Sin F1 Q3 Coeff | -32767 | 0 |
| Sin F1 Q4 Coeff | 0 | -28377 |
| Sin F1 Q5 Coeff | 32767 | -28377 |
| Cos F1 Q0 Coeff | 32767 | 32767 |
| Cos F1 Q1 Coeff | 0 | 16384 |
| Cos F1 Q2 Coeff | -32767 | -16384 |
| Cos F1 Q3 Coeff | 0 | -32767 |
| Cos F1 Q4 Coeff | 32767 | -16384 |
| Cos F1 Q5 Coeff | 0 | 16384 |
| De-aliasing Frequency | 4 quads | 6 quads |
| Sin F2 Q0 Coeff | 0 | 0 |
| Sin F2 Q1 Coeff | 32767 | 28377 |
| Sin F2 Q2 Coeff | 0 | 28377 |
| Sin F2 Q3 Coeff | -32767 | 0 |
| Sin F2 Q4 Coeff | 0 | -28377 |
| Sin F2 Q5 Coeff | 32767 | -28377 |
| Cos F2 Q0 Coeff | 32767 | 32767 |
| Cos F2 Q1 Coeff | 0 | 16384 |
| Cos F2 Q2 Coeff | -32767 | -16384 |
| Cos F2 Q3 Coeff | 0 | -32767 |
| Cos F2 Q4 Coeff | 32767 | -16384 |
| Cos F2 Q5 Coeff | 0 |
16384 |
Default values:
| Base Frequency | 4 quads | 6 quads |
| Sin F1 Q0 Coeff | 0 | 0 |
| Sin F1 Q1 Coeff | 32767 | 28377 |
| Sin F1 Q2 Coeff | 0 | -28377 |
| Sin F1 Q3 Coeff | -32767 | 0 |
| Sin F1 Q4 Coeff | 0 | 28377 |
| Sin F1 Q5 Coeff | 0 | -28377 |
| Cos F1 Q0 Coeff | 32767 | 32767 |
| Cos F1 Q1 Coeff | 0 | 16384 |
| Cos F1 Q2 Coeff | -32767 | 16384 |
| Cos F1 Q3 Coeff | 0 | 32767 |
| Cos F1 Q4 Coeff | 0 | 16384 |
| Cos F1 Q5 Coeff | 0 | 16384 |
| De-aliasing Frequency | 4 quads | 6 quads |
| Sin F2 Q0 Coeff | 0 | 0 |
| Sin F2 Q1 Coeff | 32767 | 28377 |
| Sin F2 Q2 Coeff | 0 | -28377 |
| Sin F2 Q3 Coeff | -32767 | 0 |
| Sin F2 Q4 Coeff | 0 | 28377 |
| Sin F2 Q5 Coeff | 0 | -28377 |
| Cos F2 Q0 Coeff | 32767 | 32767 |
| Cos F2 Q1 Coeff | 0 | 16384 |
| Cos F2 Q2 Coeff | -32767 | 16384 |
| Cos F2 Q3 Coeff | 0 | 32767 |
| Cos F2 Q4 Coeff | 0 | 16384 |
| Cos F2 Q5 Coeff | 0 | 16384 |
I'm guessing in the case of 4 Quads that coefficient Q4 and Q5 are not needed so they are left at 0. Could you confirm this?
Where I have concerns is with 6 Quads case. The signs don't match. What are the right values and if it's not the equation results, what's wrong them?
Thanks,
