ST7LITEU09 datasheet(23/115 Pages) STMICROELECTRONICS

部件名	ST7LITEU09

功能描述	8-bit MCU with single voltage Flash memory, ADC, timers

PDF	115 Pages

Scroll/Zoom	100%

制造商	STMICROELECTRONICS [STMicroelectronics]

网页	http://www.st.com

标志

23 / 115 page

ST7LITEU05 ST7LITEU09

23/115

SUPPLY, RESET AND CLOCK MANAGEMENT (Cont’d)

– 2. Using a 4-bit counter, wait until 8 internal RC

cycles have elapsed. The counter is running on

internal RC clock.

– 3. Wait till the AWU_FLAG is cleared (1AWU RC

cycle) and the RC_FLAG is set (2 RC cycles)

– 4. The switch to the internal RC clock is made at

the positive edge of the internal RC clock signal

– 5. Once the switch is made, the AWU RC is

stopped

Notes:

1. When the internal RC is not selected, it is

stopped so as to save power consumption.

2. When the internal RC is selected, the AWU RC

is turned on by hardware when entering Auto

Wake-Up from Halt mode.

3. When the external clock is selected, the AWU

RC oscillator is always on.

Figure 13. Clock Switching

Internal RC

AWU RC

Set RC/AWU

Poll AWU_FLAG until set

Internal RC

Reset RC/AWU

Poll RC_FLAG until set

AWU RC

ST7LITEU09 数据表(PDF) 23 Page - STMicroelectronics