ST72321AR7 STMicroelectronics, ST72321AR7 Datasheet - Page 147

• Manufacturer Part Number: ST72321AR7
• Description: 8-BIT MCU WITH NESTED INTERRUPTS, FLASH,10-BIT ADC, FIVE TIMERS, SPI, SCI, I2C INTERFACE
• Manufacturer: STMicroelectronics

Specifications of ST72321AR7

• Hdflash Endurance: 100 cycles, data retention
• Clock Sources: crystal/ceramic resonator oscillators, internal RC oscillator, clock security system and bypass for external clock
• Four Power Saving Modes: Halt, Active-Halt,Wait and Slow
• Main Clock Controller With: Real time base, Beep and Clock-out capabilities
• Two 16-bit Timers With: 2 input captures, 2 output compares, external clock input on one timer, PWM and pulse generator modes
• 8-bit Pwm Auto-reload Timer With: 2 input captures, 4 PWM outputs, output compare and time base interrupt, external clock with event detector

CLOCK AND TIMING CHARACTERISTICS (Cont’d)
12.5.3 Crystal and Ceramic Resonator Oscillators
The ST7 internal clock can be supplied with four
different Crystal/Ceramic resonator oscillators. All
the information given in this paragraph is based on
characterization results with specified typical ex-
ternal components. In the application, the resona-
tor and the load capacitors have to be placed as
Notes:
1. The oscillator selection can be optimized in terms of supply current using an high quality resonator with small R
Refer to crystal/ceramic resonator manufacturer for more details.
2. Data based on characterisation results, not tested in production.
f
R
C
C
i
2
OSC
Symbol
Symbol
F
L1
L2
Oscillator Frequency
Feedback resistor
Recommended load capacitance ver-
sus equivalent serial resistance of the
crystal or ceramic resonator (R
OSC2 driving current
Parameter
Parameter
2)
1)
V
V
DD
IN
S
)
=V
=5V
SS
LP: Low power oscillator
MP: Medium power oscillator
MS: Medium speed oscillator
HS: High speed oscillator
R
R
R
R
S
S
S
S
=200Ω
=200Ω
=200Ω
=100Ω
Conditions
close as possible to the oscillator pins in order to
minimize output distortion and start-up stabiliza-
tion time. Refer to the crystal/ceramic resonator
manufacturer for more details (frequency, pack-
age, accuracy...).
LP oscillator
MP oscillator
MS oscillator
HS oscillator
Conditions
ST72321Rx ST72321ARx ST72321Jx
LP oscillator
MP oscillator
MS oscillator
HS oscillator
Min
Typ
>2
>4
>8
20
22
22
18
15
160
310
610
1
80
Max
Max
16
40
56
46
33
33
150
250
460
910
2
4
8
147/193
S
MHz
Unit
Unit
kΩ
pF
μA
value.