Cypress FM4 Series - Page 194

CHAPTER 6: Low Power Consumption Mode
194 FM4 Peripheral Manual, Doc. No. 002-04856 Rev. *E
Overview of Deep Standby RTC Mode
Deep standby RTC mode is classified as a deep standby mode. In deep standby RTC mode, all
oscillators stop except for the sub oscillator. All functions stop operating except for the RTC and the Low
Voltage Detection Circuit. The power supply for CPUs, on-chip Flash memory, on-chip SRAM0/1/2* and
peripherals excluding the RTC, the Low Voltage Detection Circuit and GPIO are turned off inside the chip.
Overview of Deep Standby Stop Mode
Deep standby stop mode is classified as a deep standby mode. In deep standby stop mode, all oscillators
stop. All functions stop operating except for the Low Voltage Detection Circuit. The power supply for
CPUs, on-chip Flash memory, SRAM0/1/2* and peripherals excluding the RTC, the Low Voltage
Detection Circuit and GPIO are turned off inside the chip.
*: Data in SRAM2 can be retained.
If the setting for retaining data in SRAM2 is done, the power supply for SRAM2 is turned on.
Relationship between CPU Operation Modes and Current Consumption
Figure 1-1 illustrates the relationship between CPU operation modes and current consumption.
Figure 1-1 Relationship between CPU Operation Modes and Current Consumption
PLL run mode
Main run mode
High speed CR
run mode
Sub run mode
Low speed CR
run mode
Current consumption
PLL sleep mode
Main sleep
mode
High speed CR
sleep mode
Sub sleep mode
Low speed CR
sleep mode
PLL timer mode
Main timer mode
High speed CR
timer mode
Sub timer mode
Low speed CR
timer mode
RTC mode
Standby mode
Deep standby RTC
mode
Deep standby stop
mode
Deep standby mode
STOP mode
Note:
− Figure 1-1 shows only the relationship among device operation modes in terms of the size of
current consumption. The actual size of current consumption varies according to the oscillators
used and PLL starting conditions in a CPU operation mode, and clock configuration such as the
frequency selected.