ST72321AR6-Auto STMicroelectronics, ST72321AR6-Auto Datasheet - Page 62

• Manufacturer Part Number: ST72321AR6-Auto
• Description: 8-bit MCU for automotive with 32 Kbyte Flash, 10-bit ADC, timers, SPI, SCI and I2C interfaces
• Manufacturer: STMicroelectronics

Specifications of ST72321AR6-Auto

• Hdflash Endurance: 100 cycles, data retention 20 years
• Clock Sources: crystal/ceramic resonator oscillators, internal RC oscillator and bypass for external clock
• 4 Power Saving Modes: Halt, Active Halt, Wait and Slow

Power saving modes
8
8.1
8.2
Note:
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Power saving modes
Introduction
To give a large measure of flexibility to the application in terms of power consumption, four
main power saving modes are implemented in the ST7 (see
Wait), Active Halt and Halt.
After a RESET the normal operating mode is selected 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 (f
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
Slow mode
This mode has two targets:
●
●
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 (f
In this mode, the master clock frequency (f
and peripherals are clocked at this lower frequency (f
Slow Wait mode is activated when entering the Wait mode while the device is already in
Slow mode.
To reduce power consumption by decreasing the internal clock in the device,
To adapt the internal clock frequency (f
Doc ID 13829 Rev 1
ACTIVE HALT
SLOW WAIT
POWER CONSUMPTION
SLOW
WAIT
HALT
OSC2
RUN
CPU
) to the available supply voltage.
) can be divided by 2, 4, 8 or 16. The CPU
Low
High
CPU
).
Figure
OSC2
22): Slow, Wait (Slow
).
ST72321xx-Auto
CPU
).