Electronic component search and free download site.
Transistors,MosFET ,Diode,Integrated circuits

ST72324 View Datasheet(PDF) - STMicroelectronics

Part NameDescriptionManufacturer
ST72324 5V RANGE 8-BIT MCU WITH 8 TO 32K FLASH, 10-BIT ADC, 4 TIMERS, SPI, SCI INTERFACE ST-Microelectronics
STMicroelectronics ST-Microelectronics
ST72324 Datasheet PDF : 163 Pages
First Prev 31 32 33 34 35 36 37 38 39 40 Next Last
ST72324
8 POWER SAVING MODES
8.1 INTRODUCTION
To give a large measure of flexibility to the applica-
tion in terms of power consumption, four main
power saving modes are implemented in the ST7
(see Figure 22): SLOW, WAIT (SLOW WAIT), AC-
TIVE HALT and HALT.
After a RESET the normal operating mode is se-
lected by default (RUN mode). This mode drives
the device (CPU and embedded peripherals) by
means of a master clock which is based on the
main oscillator frequency divided or multiplied by 2
(fOSC2).
From RUN mode, the different power saving
modes may be selected by setting the relevant
register bits or by calling the specific ST7 software
instruction whose action depends on the oscillator
status.
Figure 22. Power Saving Mode Transitions
High
RUN
8.2 SLOW MODE
This mode has two targets:
– To reduce power consumption by decreasing the
internal clock in the device,
– To adapt the internal clock frequency (fCPU) to
the available supply voltage.
SLOW mode is controlled by three bits in the
MCCSR register: the SMS bit which enables or
disables Slow mode and two CPx bits which select
the internal slow frequency (fCPU).
In this mode, the master clock frequency (fOSC2)
can be divided by 2, 4, 8 or 16. The CPU and pe-
ripherals are clocked at this lower frequency
(fCPU).
Note: SLOW-WAIT mode is activated when enter-
ing the WAIT mode while the device is already in
SLOW mode.
Figure 23. SLOW Mode Clock Transitions
fCPU
fOSC2/2
fOSC2/4
fOSC2
SLOW
WAIT
SLOW WAIT
ACTIVE HALT
fOSC2
CP1:0
00
01
SMS
NEW SLOW
FREQUENCY
REQUEST
NORMAL RUN MODE
REQUEST
HALT
Low
POWER CONSUMPTION
40/163
1
Direct download click here

 

Share Link : 
All Rights Reserved© datasheetq.com 2015 - 2019  ] [ Privacy Policy ] [ Request Datasheet  ] [ Contact Us ]