ST7FL15F1MAE STMICROELECTRONICS [STMicroelectronics], ST7FL15F1MAE Datasheet - Page 24

• Manufacturer Part Number: ST7FL15F1MAE
• Description: 8-bit MCU for automotive with single voltage Flash/ROM memory, data EEPROM, ADC, 5 timers, SPI
• Manufacturer: STMICROELECTRONICS [STMicroelectronics]

ST7L15, ST7L19
SUPPLY, RESET AND CLOCK MANAGEMENT (cont’d)
7.4 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):
■
■
■
The associated hardware configurations are
shown in
CAL CHARACTERISTICS
7.4.1 External Clock Source
In external clock mode, a clock signal (square, si-
nus or triangle) with ~50% duty cycle must drive
the OSC1 pin while the OSC2 pin is tied to ground.
Note: When the Multi-Oscillator is not used, PB4
is selected by default as the external clock.
7.4.2 Crystal/Ceramic Oscillators
In this mode, with a self-controlled gain feature, an
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 must be placed as close as possi-
ble to the oscillator pins to minimize output distor-
tion and start-up stabilization time. The loading ca-
pacitance 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.
7.4.3 Internal RC Oscillator
In this mode, the tunable 1% RC oscillator is the
main clock source. The two oscillator pins must be
tied to ground if dedicated to oscillator use, other-
wise they are general purpose I/O.
The calibration is done through the RCCR[7:0] and
SICSR[6:5] registers.
24/138
1
An external source
Crystal or ceramic resonator oscillators
An internal high frequency RC oscillator
Table
4. Refer to
for more details.
Section 13 ELECTRI-
Table 4. ST7 Clock Sources
C
L1
EXTERNAL
Hardware Configuration
SOURCE
OSC1
OSC1
OSC1
CAPACITORS
LOAD
ST7
ST7
ST7
OSC2
OSC2
OSC2
C
L2