ST72F324BJ STMICROELECTRONICS [STMicroelectronics], ST72F324BJ Datasheet - Page 26

• Manufacturer Part Number: ST72F324BJ
• Description: 8-bit MCU, 3.8 to 5.5 V operating range with 8 to 32 Kbyte Flash/ROM, 10-bit ADC, 4 timers, SPI, SCI
• Manufacturer: STMICROELECTRONICS [STMicroelectronics]

Supply, reset and clock management
6
6.1
6.2
Caution:
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Supply, reset and clock management
Introduction
The device includes a range of utility features for securing the application in critical
situations (for example in case of a power brown-out), and reducing the number of external
components. An overview is shown in
For more details, refer to dedicated parametric section.
Main features
●
●
●
●
PLL (phase locked loop)
If the clock frequency input to the PLL is in the range 2 to 4 MHz, the PLL can be used to
multiply the frequency by two to obtain an f
byte. If the PLL is disabled, then f
The PLL is not recommended for applications where timing accuracy is required.
Furthermore, it must not be used with the internal RC oscillator.
Figure 11. PLL block diagram
Optional Phase Locked Loop (PLL) for multiplying the frequency by 2 (not to be used
with internal RC oscillator in order to respect the max. operating frequency)
Multi-Oscillator clock management (MO)
–
–
Reset Sequence Manager (RSM)
System Integrity management (SI)
–
–
5 crystal/ceramic resonator oscillators
1 Internal RC oscillator
Main supply low voltage detection (LVD)
Auxiliary voltage detector (AVD) with interrupt capability for monitoring the main
supply
f
OSC
OSC2
PLL x 2
Figure
= f
/ 2
OSC
OSC2
12.
/2.
of 4 to 8 MHz. The PLL is enabled by option
PLL option bit
0
1
f
OSC2
ST72324B