Internal RC oscillator calibration

AN4067

12/27

DocID022913 Rev 2

Figure 7. Hardware connection using LSE as the reference frequency

1.

TI1_RPM: TIM14 input 1 remapping

2.

TI1_RPM: Timer input 1

3.

IC1PS: Input capture 1 prescaled

Note:

It is also possible to use MCO for this purpose.

3.2.2

Case where another source is used as the reference frequency to



measure HSI

Any signal with an accurate frequency can be used for the internal oscillator calibration, and

the external signal is one of the possibilities.

As shown in Figure 8 below, the reference signal should be connected to Timer 14

channel 1.

Figure 8. Hardware connection using external reference frequency

1.

TI1_RPM: TIM14 input 1 remapping

2.

TI1: Timer input 1

3.

IC1PS: Input capture 1 prescaled