AN3029 datasheet(13/42 Pages) STMICROELECTRONICS

部件名	AN3029

功能描述	Getting started with STM8L and STM8AL

PDF	42 Pages

Scroll/Zoom	100%

制造商	STMICROELECTRONICS [STMicroelectronics]

网页	http://www.st.com

标志

13 / 42 page

DocID16139 Rev 5

13/42

AN3029

Clock management

Figure 6. Crystal/ceramic resonators

1. To avoid exceeding the maximum value of CL1 and CL2 (15 pF), it is strongly recommended to use a

resonator with a load capacitance CL = 7 pF. To fine-tune the choice, refer to the gmcrit calculation in

AN2867 (Oscillator design guide for ST microcontrollers).

2. OSC32_IN and OSC32_OUT pins can be used also as GPIO, but it is recommended not to use them as

both RTC and GPIO pins in the same application.

3. The value of REXT depends on the crystal characteristics. A 0 Ω resistor works with most oscillators. A

typical value is in the range 5 to 6 RS. To fine-tune the REXT value refer to AN2867 (Oscillator design guide

for ST microcontrollers).

OSC32_OUT

OSC32_IN

ai15764

CL1

CL2

Microcontroller

REXT

(3)

AN3029 数据表(PDF) 13 Page - STMicroelectronics