ST7MC1xx/ST7MC2xx
6 SUPPLY, RESET AND CLOCK MANAGEMENT
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 re-
ducing the number of external components. An
overview is shown in Figure 13.
For more details, refer to dedicated parametric
section.
Main features
■ Reset Sequence Manager (RSM)
■ 1 Crystal/Ceramic resonator oscillator
■ System Integrity Management (SI)
– Main supply Low voltage detection (LVD)
– Auxiliary Voltage detector (AVD) with interrupt
capability for monitoring the main supply
– Clock Security System (CSS) with the VCO of
the PLL, providing a backup safe oscillator
– Clock Detector
– PLL which can be used to multiply the fre-
quency by 2 if the clock frequency input is
8MHz
Figure 13. Clock, Reset and Supply Block Diagram
SYSTEM INTEGRITY MANAGEMENT
OSC2
OSC1
fOSC
CLOCK SECURITY SYSTEM
OSCILLATOR
1/2
fOSC
DIV2 OPT
8Mhz PLL
Safeosc
16Mhz
lock
fCLK MAIN CLOCK fCPU
CONTROLLER
WITH REALTIME
CLOCK (MCC/RTC)
fMTC
CKSEL
SICSR, page 1
PA
GE
0
VCO LO PLL
EN CK EN
0
CK
SEL
0
Clock Detector
RESET
RESET SEQUENCE
MANAGER
(RSM)
AVD Interrupt Request
SICSR, page 0
PA AVD AVD LVD
GE IE F RF
0
CSS CSS WDG
IE D RF
WATCHDOG
TIMER (WDG)
VSS
VDD*
CSS Interrupt Request
LOW VOLTAGE
DETECTOR
(LVD)
AUXILIARY VOLTAGE
DETECTOR
(AVD)
* It is recommended to decouple the power supply by placing a 0.1µF capacitor as close as possible to VDD
28/309
1