[77] CLOCK: RC oscillator is not calibrated when first started

This anomaly applies to IC Rev. Engineering B, build codes QFAA-BA0, CHAA-AA0.

It was inherited from the previous IC revision Engineering A.

Symptoms

The LFCLK RC oscillator frequency can have a frequency error of up to -25 to +40% after reset. A +/- 2% error is stated in the Product Specification.

Conditions

Always

Consequences

The LFCLK RC oscillator frequency is inaccurate.

Workaround

Calibrate the LFCLK RC oscillator before its first use after a reset.