ST7FL15F1MAE STMICROELECTRONICS [STMicroelectronics], ST7FL15F1MAE Datasheet - Page 27

• 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]

SUPPLY, RESET AND CLOCK MANAGEMENT (cont’d)
The RESET pin is an asynchronous signal which
plays a major role in EMS performance. In a noisy
environment, it is recommended to follow the
guidelines mentioned in
CHARACTERISTICS.
7.5.3 External Power-On RESET
If the LVD is disabled by the option byte, to start up
the microcontroller correctly, the user must use an
external reset circuit to ensure that the reset signal
is held low until V
specified for the selected f
A proper reset signal for a slow rising V
can generally be provided by an external RC net-
work connected to the RESET pin.
Figure 15. RESET Sequences
WATCHDOG
RESET
EXTERNAL
RESET
SOURCE
RESET PIN
V
V
IT+(LVD)
IT-(LVD)
DD
V
RUN
is over the minimum level
DD
Section 13 ELECTRICAL
OSC
ACTIVE PHASE
frequency.
RESET
LVD
DD
supply
RUN
t
h(RSTL)in
7.5.4 Internal Low Voltage Detector (LVD)
RESET
Two different RESET sequences caused by the in-
ternal LVD circuitry can be distinguished:
■
■
The device RESET pin acts as an output that is
pulled low when V
V
The LVD filters spikes on V
avoid parasitic resets.
7.5.5 Internal Watchdog RESET
The RESET sequence generated by an internal
Watchdog counter overflow is shown in
Starting from the Watchdog counter underflow, the
device RESET pin acts as an output that is pulled
low during at least t
DD
WATCHDOG UNDERFLOW
Power-On RESET
Voltage Drop RESET
ACTIVE
PHASE
EXTERNAL
< V
RESET
IT-
(falling edge) as shown in
INTERNAL RESET (256 or 4096 t
VECTOR FETCH
RUN
w(RSTL)out
DD
ACTIVE
PHASE
WATCHDOG
< V
RESET
t
DD
w(RSTL)out
IT+
.
larger than t
ST7L15, ST7L19
(rising edge) or
RUN
Figure
CPU
Figure
)
g(VDD)
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