SPRUIU1D July 2020 – December 2024 DRA821U , DRA821U-Q1
In Figure 12-397 the ECAP operating mode is almost the same as in the previous section except capture events are qualified as either rising or falling edge, this now gives both period and duty cycle information: Period1 = t3 – t1, Period2 = t5 – t3, …etc. Duty Cycle1 (on-time %) = (t2 – t1) / Period1 x 100%, etc. Duty Cycle1 (off-time %) = (t3 – t2) / Period1 x 100%, etc.
Figure 12-2578 Capture Sequence for Absolute Time-Stamp, Rising and Falling Edge Detect| Register | Bit | Value |
|---|---|---|
| ECCTL1 | CAP1POL | EC_RISING |
| ECCTL1 | CAP2POL | EC_FALLING |
| ECCTL1 | CAP3POL | EC_RISING |
| ECCTL1 | CAP4POL | EC_FALLING |
| ECCTL1 | CTRRST1 | EC_ABS_MODE |
| ECCTL1 | CTRRST2 | EC_ABS_MODE |
| ECCTL1 | CTRRST3 | EC_ABS_MODE |
| ECCTL1 | CTRRST4 | EC_ABS_MODE |
| ECCTL1 | CAPLDEN | EC_ENABLE |
| ECCTL1 | PRESCALE | EC_DIV1 |
| ECCTL2 | CAP_APWM | EC_CAP_MODE |
| ECCTL2 | CONT_ONESHT | EC_CONTINUOUS |
| ECCTL2 | SYNCO_SEL | EC_SYNCO_DIS |
| ECCTL2 | SYNCI_EN | EC_DISABLE |
| ECCTL2 | TSCTRSTOP | EC_RUN |