Dynamic Voltage Scaling Management - ST STM32G0 1 Series Reference Manual

RM0444
4.1.4

Dynamic voltage scaling management

The dynamic voltage scaling is a power management technique which consists in
increasing or decreasing the voltage used for the digital peripherals (V
the application performance and power consumption needs.
Dynamic voltage scaling to increase V
device performance.
Dynamic voltage scaling to decrease V
save power, particularly in laptop and other mobile devices where the energy comes from a
battery and is thus limited.
Two voltage ranges are available:
• Range 1: High-performance range
The main regulator provides a typical output voltage at 1.2 V. The system clock
frequency can be up to 64 MHz. The Flash access time for read access is minimum,
write and erase operations are possible.
• Range 2: Low-power range
The main regulator provides a typical output voltage at 1.0 V. The system clock
frequency can be up to 16 MHz.The Flash memory access time for a read access is
increased as compared to Range 1; write and erase operations are not possible.
The voltage scaling is selected through the VOS bit in the PWR_CR1 register.
The sequence to go from Range 1 to Range 2 is:
1. Reduce the system frequency to a value lower than 16 MHz
2. Adjust number of wait states according new frequency target in Range 2 (LATENCY
bits in the FLASH_ACR).
3. Program the VOS[1:0] bits to 10 in the
The sequence to go from Range 2 to Range 1 is:
1. Program the VOS[1:0] bits to 01 in the
2. Wait until the VOSF flag is cleared in the
3. Adjust number of wait states according new frequency target in Range 1 (LATENCY
bits in the
4. Increase the system frequency.
FLASH access control register
RM0444 Rev 5
is known as overvolting. It allows to improve the
CORE
is known as undervolting. It is performed to
CORE
Power control register 1
Power control register 1
Power status register 2
(FLASH_ACR).
Power control (PWR)
), according to
CORE
(PWR_CR1).
(PWR_CR1).
(PWR_SR2).
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