ST72344S4 STMicroelectronics, ST72344S4 Datasheet - Page 45

• Manufacturer Part Number: ST72344S4
• Description: 8-bit MCU
• Manufacturer: STMicroelectronics

Specifications of ST72344S4

• Up To 16 Kbytes Program Memory: single voltage extended Flash (XFlash) with readout and write protection, in-circuit and inapplication programming (ICP and IAP). 10K write/erase cycles guaranteed, data retention
• 256 Bytes Data Eeprom With Readout Protection. 300k Write/erase Cycles Guaranteed, Data Retention: 20 years at 55 °C.
• Clock Sources: crystal/ceramic resonator oscillators, high-accuracy internal RC oscillator or external clock
• 5 Power-saving Modes: Slow, Wait, Halt, Auto-wakeup from Halt and Active-halt
• 16-bit Timer A With: 1 input capture, 1 output compares, external clock input, PWM and pulse generator modes
• 16-bit Timer B With: 2 input captures, 2 output compares, PWM and pulse generator modes

ST72344xx ST72345xx
7.3.3
Note:
Caution:
7.4
7.4.1
Internal RC oscillator
The device contains a high-precision internal RC oscillator. It must be calibrated to obtain
the frequency required in the application. This is done by software writing a calibration value
in the RCCRH and RCCRL Registers.
Whenever the microcontroller is reset, the RCCR returns to its default value (FF 03h), i.e.
each time the device is reset, the calibration value must be loaded in the RCCRH and
RCCRL registers. Predefined calibration values are stored in XFlash for 3 and 5V V
supply voltages at 25 °C, as shown in the following table:
Table 9.
To improve clock stability, it is recommended to place a decoupling capacitor between the
V
These two 10-bit values are systematically programmed by ST.
RCCR0 and RCCR1 calibration values will be erased if the read-out protection bit is reset
after it has been set. See
If the voltage or temperature conditions change in the application, the frequency may need
to be recalibrated.
Refer to application note AN1324 for information on how to calibrate the RC frequency using
an external reference signal.
Register description
RC control register (RCCRH)
Reset value: 1111 1111 (FFh)
Bits 7:0 = CR[9:2] RC oscillator frequency adjustment bits
DD
CR9
and V
7
RCCR0
RCCR1
RCCR
SS
Calibration values
pins.
CR8
Memory protection on page
CR7
Doc ID 12321 Rev 5
f
f
Conditions
RC
RC
T
T
V
V
A
A
DD
DD
= 25 °C
= 1 MHz
= 25 °C
= 1 MHz
= 5 V
= 3 V
CR6
Read/Write
CR5
Supply, reset and clock management
29.
CR4
BEE0, BEE1
BEE4, BEE5
Address
CR3
DD
CR2
0
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