ST7LITE49K2 STMicroelectronics, ST7LITE49K2 Datasheet - Page 42

• Manufacturer Part Number: ST7LITE49K2
• Description: 8-bit MCU
• Manufacturer: STMicroelectronics

Specifications of ST7LITE49K2

• 8 Kbytes Single Voltage Extended Flash (xflash) Program Memory With Read-out Protection In-circuit Programming And In-application Programming (icp And Iap) Endurance: 10K write/erase cycles guaranteed Data retention
• 256 Bytes Data Eeprom With Read-out Protection. 300k Write/erase Cycles Guaranteed, Data Retention: 20 years at 55 °C.
• Clock Sources: Internal trimmable 8 MHz RC oscillator, auto-wakeup internal low power - low frequency oscillator, crystal/ceramic resonator or external clock
• Five Power Saving Modes: Halt, Active-halt, Auto-wakeup from Halt, Wait and Slow

Supply, reset and clock management
7.2
7.2.1
Note:
7.2.2
7.2.3
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Multi-oscillator (MO)
The main clock of the ST7 can be generated by four different source types coming from the
multi-oscillator block (1 to 16 MHz):
●
●
●
Each oscillator is optimized for a given frequency range in terms of consumption and is
selectable through the option byte. The associated hardware configurations are shown in
Table
External clock source
In this external clock mode, a clock signal (square, sinus or triangle) with ~50% duty cycle
has to drive the OSC1 pin while the OSC2 pin is tied to ground.
When the Multi-Oscillator is not used OSCI1 and OSCI2 must be tied to ground, and PB1 is
selected by default as the external clock.
Crystal/ceramic oscillators
In this mode, with a self-controlled gain feature, oscillator of any frequency from 1 to 16 MHz
can be placed on OSC1 and OSC2 pins. This family of oscillators has the advantage of
producing a very accurate rate on the main clock of the ST7. In this mode of the multi-
oscillator, the resonator and the load capacitors have to be placed as close as possible to
the oscillator pins in order to minimize output distortion and start-up stabilization time. The
loading capacitance values must be adjusted according to the selected oscillator.
These oscillators are not stopped during the RESET phase to avoid losing time in the
oscillator start-up phase.
Internal RC oscillator
In this mode, the tunable 1% RC oscillator is used as main clock source. The two oscillator
pins have to be tied to ground.
The calibration is done through the RCCR[7:0] and SICSR[6:5] registers.
An external source
5 different configurations for crystal or ceramic resonator oscillators
An internal high frequency RC oscillator
6. Refer to the electrical characteristics section for more details.
ST7LITE49K2