STM8AF528ATAY Datasheet, PDF (18/114 Pages) STMicroelectronics – Automotive 8-bit MCU, with up to 128 Kbytes Flash, data EEPROM, 10-bit ADC, timers, LIN, CAN, USART, SPI, I2C, 3 to 5.5 V

Product overview
STM8AF52/62xx, STM8AF51/61xx
5.5.3
5.5.4
5.5.5
5.5.6
128 kHz low-speed internal RC oscillator (LSI)
The frequency of this clock is 128 kHz and it is independent from the main clock. It drives
the independent watchdog or the AWU wakeup timer.
In systems which do not need independent clock sources for the watchdog counters, the
128 kHz signal can be used as the system clock. This configuration has to be enabled by
setting an option byte (OPT3/OPT3N, bit LSI_EN).
24 MHz high-speed external crystal oscillator (HSE)
The external high-speed crystal oscillator can be selected to deliver the main clock in
normal Run mode. It operates with quartz crystals and ceramic resonators.
• Frequency range: 1 MHz to 24 MHz
• Crystal oscillation mode: preferred fundamental
• I/Os: standard I/O pins multiplexed with OSCIN, OSCOUT
External clock input
An external clock signal can be applied to the OSCIN input pin of the crystal oscillator. The
frequency range is 0 to 24 MHz.
Clock security system (CSS)
The clock security system protects against a system stall in case of an external crystal clock
failure.
In case of a clock failure an interrupt is generated and the high-speed internal clock (HSI) is
automatically selected with a frequency of 2 MHz (16 MHz/8).
Table 6. Peripheral clock gating bits (CLK_PCKENR1)
Control bit
Peripheral
PCKEN17
PCKEN16
PCKEN15
PCKEN14
TIM1
TIM3
TIM2
TIM4
PCKEN13
PCKEN12
PCKEN11
PCKEN10
LINUART
USART
SPI
I²C
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DocID14395 Rev 10