ST72F321J9T6 STMicroelectronics, ST72F321J9T6 Datasheet - Page 28

• Manufacturer Part Number: ST72F321J9T6
• Description: MCU 8BIT 60KB FLASH 44TQFP
• Manufacturer: STMicroelectronics
• Series: ST7r

Specifications of ST72F321J9T6

• Core Processor: ST7
• Core Size: 8-Bit
• Speed: 8MHz
• Connectivity: I²C, SCI, SPI
• Peripherals: LVD, POR, PWM, WDT
• Number Of I /o: 32
• Program Memory Size: 60KB (60K x 8)
• Program Memory Type: FLASH
• Ram Size: 2K x 8
• Voltage - Supply (vcc/vdd): 3.8 V ~ 5.5 V
• Data Converters: A/D 16x10b
• Oscillator Type: Internal
• Operating Temperature: -40°C ~ 85°C
• Package / Case: 44-TQFP, 44-VQFP
• Processor Series: ST72F3x
• Core: ST7
• Data Bus Width: 8 bit
• Data Ram Size: 2048 B
• Interface Type: I2C, SCI, SPI
• Maximum Clock Frequency: 8 MHz
• Number Of Programmable I/os: 48
• Number Of Timers: 5
• Operating Supply Voltage: 3.8 V to 5.5 V
• Maximum Operating Temperature: + 85 C
• Mounting Style: SMD/SMT
• Development Tools By Supplier: ST7F521-IND/USB, ST7232X-EVAL, ST7MDT20-DVP3, ST7MDT20-DVP3, STX-RLINK
• Minimum Operating Temperature: - 40 C
• On-chip Adc: 10 bit
• For Use With: 497-5046 - KIT TOOL FOR ST7/UPSD/STR7 MCU
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Eeprom Size: -
• Lead Free Status / Rohs Status: Details
• Other names: 497-4844

ST72321Rx ST72321ARx ST72321Jx
6.4 SYSTEM INTEGRITY MANAGEMENT (SI)
The System Integrity Management block contains
the Low Voltage Detector (LVD),
age Detector (AVD) functions. It is managed by
the SICSR register.
6.4.1 Low Voltage Detector (LVD)
The Low Voltage Detector function (LVD) gener-
ates a static reset when the V
below a V
secures the power-up as well as the power-down
keeping the ST7 in reset.
The V
than the V
to avoid a parasitic reset when the MCU starts run-
ning and sinks current on the supply (hysteresis).
The LVD Reset circuitry generates a reset when
V
The LVD function is illustrated in
The voltage threshold can be configured by option
byte to be low, medium or high.
Provided the minimum V
the oscillator frequency) is above V
can only be in two modes:
Figure 15. Low Voltage Detector vs Reset
28/193
DD
– V
– V
RESET
is below:
IT-
IT+
IT-
V
V
reference value for a voltage drop is lower
when V
when V
IT+
IT-
IT+
IT-
reference value for power-on in order
reference value. This means that it
V
DD
DD
DD
is falling
is rising
DD
value (guaranteed for
DD
Figure
supply voltage is
Auxiliary Volt-
IT-
, the MCU
15.
In these conditions, secure operation is always en-
sured for the application without the need for ex-
ternal reset hardware.
During a Low Voltage Detector Reset, the RESET
pin is held low, thus permitting the MCU to reset
other devices.
Notes:
The LVD allows the device to be used without any
external RESET circuitry.
If the medium or low thresholds are selected, the
detection may occur outside the specified operat-
ing voltage range. Below 3.8V, device operation is
not guaranteed.
The LVD is an optional function which can be se-
lected by option byte.
It is recommended to make sure that the V
ply voltage rises monotonously when the device is
exiting from Reset, to ensure the application func-
tions properly.
V
– under full software control
– in static safe reset
hys
DD
sup-