Internal High-Frequency Oscillator Control A
Name:
OSCHFCTRLA
Offset:
0x08
Reset:
0x0C
Access:
Configuration Change Protection
Bit76543210
RUNSTDBYFRQSEL[3:0]AUTOTUNE
AccessR/WR/WR/WR/WR/WR/W
Reset000110

Bit 7 – RUNSTDBY: Run Standby

Run Standby

This bit controls whether the internal high-frequency oscillator (OSCHF) is always running or not.

Notes:
  1. 1.The requesting peripheral, or the main clock, must take the oscillator start-up time into account.
  2. 2.The oscillator signal is only available if requested and will be available after two OSCHF cycles.
ValueDescription
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

Frequency Select

This bit field controls the output frequency of the internal high-frequency oscillator (OSCHF).
Value Name Description
0x0 1 MHz 1 MHz output
0x1 2 MHz 2 MHz output
0x2 3 MHz 3 MHz output
0x3 4 MHz 4 MHz output (default)
0x4 - Reserved
0x5 8 MHz 8 MHz output
0x6 12 MHz 12 MHz output
0x7 16 MHz 16 MHz output
0x8 20 MHz 20 MHz output
0x9 24 MHz 24 MHz output
Other - Reserved

Bit 0 – AUTOTUNE: Auto-Tune Enable

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.

ValueDescription
0 The auto-tune functionality of the OSCHF oscillator is disabled
1 The auto-tune functionality of the OSCHF oscillator is enabled