ST72F264G2B6 STMicroelectronics, ST72F264G2B6 Datasheet - Page 21

• Manufacturer Part Number: ST72F264G2B6
• Description: MCU 8-BIT 8K FLASH 32-SDIP
• Manufacturer: STMicroelectronics
• Series: ST7r

Specifications of ST72F264G2B6

• Mfg Application Notes: ST7 Checksum Capability, AN1070 App Note
• Core Processor: ST7
• Core Size: 8-Bit
• Speed: 16MHz
• Connectivity: I²C, SCI, SPI
• Peripherals: LVD, POR, PWM, WDT
• Number Of I /o: 22
• Program Memory Size: 8KB (8K x 8)
• Program Memory Type: FLASH
• Ram Size: 256 x 8
• Voltage - Supply (vcc/vdd): 2.7 V ~ 5.5 V
• Data Converters: A/D 6x10b
• Oscillator Type: Internal
• Operating Temperature: -40°C ~ 85°C
• Package / Case: 32-SDIP (0.400", 10.16mm)
• Processor Series: ST72F2x
• Core: ST7
• Data Bus Width: 8 bit
• Data Ram Size: 256 B
• Interface Type: I2C, SCI, SPI
• Maximum Clock Frequency: 8 MHz
• Number Of Programmable I/os: 22
• Number Of Timers: 3
• Maximum Operating Temperature: + 85 C
• Mounting Style: Through Hole
• Development Tools By Supplier: ST7F264-IND/USB, ST72F34X-SK/RAIS, ST7MDT10-DVP3, ST7MDT10-EMU3, STX-RLINK
• Minimum Operating Temperature: - 40 C
• On-chip Adc: 10 bit, 6 Channel
• For Use With: 497-6423 - BOARD EVAL BASED ON ST72264G1497-5046 - 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: 497-5570

6.2 MULTI-OSCILLATOR (MO)
The main clock of the ST7 can be generated by
four different source types coming from the multi-
oscillator block:
■
■
■
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
electrical characteristics section for more details.
Caution: The OSC1 and/or OSC2 pins must not
be left unconnected. For the purposes of Failure
Mode and Effects Analysis, it should be noted that
if the OSC1 and/or OSC2 pins are left unconnect-
ed, the ST7 main oscillator may start and, in this
configuration, could generate an f
quency in excess of the allowed maximum
(>16MHz.), putting the ST7 in an unsafe/unde-
fined state. The product behaviour must therefore
be considered undefined when the OSC pins are
left unconnected.
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.
Crystal/Ceramic Oscillators
This family of oscillators has the advantage of pro-
ducing a very accurate rate on the main clock of
the ST7. The selection within a list of 5 oscillators
with different frequency ranges has to be done by
option byte in order to reduce consumption (refer
to
the frequency ranges). In this mode of the multi-
oscillator, the resonator and the load capacitors
have to be placed as close as possible to the oscil-
lator pins in order to minimize output distortion and
start-up stabilization time. The loading capaci-
tance 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.
an external source
5 crystal or ceramic resonator oscillators
an internal high frequency RC oscillator
Section 15.1 on page 162
Table
for more details on
3. Refer to the
OSC
clock fre-
Internal RC Oscillator
This oscillator allows a low cost solution for the
main clock of the ST7 using only an internal resis-
tor and capacitor. Internal RC oscillator mode has
the drawback of a lower frequency accuracy and
should not be used in applications that require ac-
curate timing.
In this mode, the two oscillator pins have to be tied
to ground.
Related documentation
AN1530: Accurate timebase for low cost ST7 ap-
plications with internal RC.
Table 3. ST7 Clock Sources
ST72260Gx, ST72262Gx, ST72264Gx
C
L1
Hardware Configuration
EXTERNAL
SOURCE
OSC1
OSC1
OSC1
CAPACITORS
LOAD
ST7
ST7
ST7
OSC2
OSC2
OSC2
C
L2
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