18.5.15 Internal High-Frequency Oscillator Control A
| Name: | OSCHFCTRLA |
| Offset: | 0x40 |
| Reset: | 0x0C |
| Property: | Configuration Change Protection |
| Bit | 7 | 6 | 5 | 4 | 3 | 2 | 1 | 0 | |
| RUNSTDBY | FRQSEL[3:0] | AUTOTUNE | |||||||
| Access | R/W | R/W | R/W | R/W | R/W | R/W | |||
| Reset | 0 | 0 | 0 | 1 | 1 | 0 | |||
Bit 7 – RUNSTDBY Run Standby
This bit controls whether the internal high-frequency oscillator (OSCHF) is always running or not.
Note:
- The requesting peripheral, or the main clock, must take the oscillator start-up time into account.
- The oscillator signal is only available if requested and will be available after two OSCHF cycles.
| Value | Description |
|---|---|
| 0 | The OSCHF oscillator will only run when requested by a peripheral or by the main clock (1) |
| 1 | The OSCHF oscillator will always run in Active, Idle and Standby sleep modes (2) |
Bits 5:2 – FRQSEL[3:0] Frequency Select
| Value | Name | Description |
|---|---|---|
| 0x0 | 1MHZ | 1 MHz output |
| 0x1 | 2MHZ | 2 MHz output |
| 0x2 | 3MHZ | 3 MHz output |
| 0x3 | 4MHZ | 4 MHz output (default) |
| 0x4 | - | Reserved |
| 0x5 | 8MHZ | 8 MHz output |
| 0x6 | 12MHZ | 12 MHz output |
| 0x7 | 16MHZ | 16 MHz output |
| 0x8 | 20MHZ | 20 MHz output |
| Other | - | Reserved |
Bit 0 – AUTOTUNE Auto-Tune Enable
This bit controls whether the 32.768 kHz crystal auto-tune functionality of the internal high-frequency oscillator (OSCHF) is enabled or not.
| Value | Description |
|---|---|
| 0 | The auto-tune functionality of the OSCHF oscillator is disabled |
| 1 | The auto-tune functionality of the OSCHF oscillator is enabled |