65.7.25 ADC Trigger Register
This register can only be written if the WPEN bit is cleared in the ADC Write Protection Mode Register.
| Name: | ADC_TRGR |
| Offset: | 0xC0 |
| Reset: | 0x00000000 |
| Property: | Read/Write |
| Bit | 31 | 30 | 29 | 28 | 27 | 26 | 25 | 24 | |
| TRGPER[15:8] | |||||||||
| Access | R/W | R/W | R/W | R/W | R/W | R/W | R/W | R/W | |
| Reset | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | |
| Bit | 23 | 22 | 21 | 20 | 19 | 18 | 17 | 16 | |
| TRGPER[7:0] | |||||||||
| Access | R/W | R/W | R/W | R/W | R/W | R/W | R/W | R/W | |
| Reset | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | |
| Bit | 15 | 14 | 13 | 12 | 11 | 10 | 9 | 8 | |
| Access | |||||||||
| Reset |
| Bit | 7 | 6 | 5 | 4 | 3 | 2 | 1 | 0 | |
| TRGMOD[2:0] | |||||||||
| Access | R/W | R/W | R/W | ||||||
| Reset | 0 | 0 | 0 | ||||||
Bits 31:16 – TRGPER[15:0] Trigger Period
Effective only if TRGMOD defines a periodic trigger.
Defines the periodic trigger period, with the following equation:
Trigger Period = (TRGPER + 1) / ADCCLK
The minimum time between two consecutive trigger events must be strictly greater than the duration time of the longest conversion sequence depending on the configuration of registers ADC_MR, ADC_CHSR, ADC_SEQRx, ADC_TSMR.
When TRGMOD is set to pen detect trigger (i.e., 100) and averaging is used (i.e., field TSAV ≠ 0 in ADC_TSMR) only one measure is performed. Thus, XRDY, YRDY, PRDY, DRDY will not rise on pen contact trigger. To achieve measurement, several triggers must be provided either by software or by setting the TRGMOD on continuous trigger (i.e., 110) until flags rise.
Bits 2:0 – TRGMOD[2:0] Trigger Mode
| Value | Name | Description |
|---|---|---|
| 0 | NO_TRIGGER | No hardware trigger enabled, only software trigger can start conversions |
| 1 | EXT_TRIG_RISE | Rising edge of the selected hardware trigger event, defined in ADC_MR.TRGSEL |
| 2 | EXT_TRIG_FALL | Falling edge of the selected hardware trigger event |
| 3 | EXT_TRIG_ANY | Any edge of the selected hardware trigger event |
| 4 | PEN_TRIG | Pen Detect Trigger (shall be selected only if PENDET is set and TSMODE > 0) |
| 5 | PERIOD_TRIG | ADC internal hardware periodic trigger (see field TRGPER) |
| 6 | CONTINUOUS | Continuous mode |