tags: [entity] type: entity topic: stm32-lower note: 18 created: 2026-07-16

updated: 2026-07-16

Note 18: Power (lower/stm32/15~20)

Projects

#	Directory	Mode	Library
15	`15_lowpower_sleep_register`	Sleep	Register
16	`16_lowpower_sleep_hal`	Sleep	HAL
17	`17_lowpower_stop_register`	Stop	Register
18	`18_lowpower_stop_hal`	Stop	HAL
19	`19_lowpower_standby_register`	Standby	Register
20	`20_lowpower_standby_hal`	Standby	HAL

Code Accuracy Audit

Path Audit

All paths are correct (no double stm32/ issue for these projects).

Sleep Mode — Register (15_lowpower_sleep_register/main.c)

Claimed by Note	Actual Code (line 45)	Match?
`SCB->SCR &= ~SCB_SCR_SLEEPDEEP`	Line 45	✅ Match
`__WFI()`	Line 48	✅ Match
Calls `enter_sleep_mode()`	Function defined lines 42-48	✅ Match
Uses `USART_Init()`, `LED_Init()`, `Delay_s()` includes	Lines 9-11	✅ Match

Note mentions SLEEPONEXIT option — actual code only implements SLEEP-NOW (SLEEPDEEP=0, immediate WFI). The SLEEP-ON-EXIT variant is described in note but not implemented in this file.

Sleep Mode — HAL (16_lowpower_sleep_hal/main.c)

Claimed by Note	Actual Code	Match?
`HAL_SuspendTick()`	Present	✅ Match
`HAL_PWR_EnterSLEEPMode(PWR_MAINREGULATOR_ON, PWR_SLEEPENTRY_WFI)`	Present	✅ Match
`HAL_ResumeTick()`	Present	✅ Match

Stop Mode — Register (17_lowpower_stop_register/main.c)

Claimed by Note	Actual Code	Match?
`SCB->SCR	= SCB_SCR_SLEEPDEEP`	Present
`RCC->APB1ENR	= RCC_APB1ENR_PWREN`	Present
`PWR->CR &= ~PWR_CR_PDDS` (Stop mode)	Present	✅ Match
`PWR->CR	= PWR_CR_LPDS` (Low-power regulator)	Present
`__WFI()`	Present	✅ Match
Wake: `SystemInit()`	Present	✅ Match
`get_clock_freq()` helper	Present (lines in file)	✅ Match

Stop Mode — HAL (18_lowpower_stop_hal/main.c)

Claimed by Note	Actual Code	Match?
`HAL_PWR_EnterSTOPMode(PWR_LOWPOWERREGULATOR_ON, PWR_SLEEPENTRY_WFI)`	Present	✅ Match
Wake: `SystemClock_Config()`	Present	✅ Match

Standby Mode — Register (19_lowpower_standby_register/main.c)

Claimed by Note	Actual Code	Match?
`SCB->SCR	= SCB_SCR_SLEEPDEEP`	Present
`PWR->CR	= PWR_CR_PDDS`	Present
`PWR->CSR	= PWR_CSR_EWUP` (PA0 wake)	Present
`__WFI()`	Present	✅ Match
Wake detection: `PWR->CSR & PWR_CSR_SBF`	Present	✅ Match
`PWR->CR	= PWR_CR_CSBF` (clear SB flag)	Present
`PWR->CR	= PWR_CR_CWUF` (clear WUF flag)	Present

Standby Mode — HAL (20_lowpower_standby_hal/main.c)

Claimed by Note	Actual Code	Match?
`__HAL_PWR_GET_FLAG(PWR_FLAG_SB)`	Present	✅ Match
`__HAL_PWR_CLEAR_FLAG(PWR_FLAG_SB)`	Present	✅ Match
`__HAL_PWR_GET_FLAG(PWR_FLAG_WU)`	Present	✅ Match
`__HAL_PWR_CLEAR_FLAG(PWR_FLAG_WU)`	Present	✅ Match
`HAL_PWR_EnableWakeUpPin(PWR_WAKEUP_PIN1)`	Present	✅ Match
`HAL_PWR_EnterSTANDBYMode()`	Present	✅ Match

PVD Configuration

Note's claim:

PWR->CR |= PWR_CR_PLS_2 | PWR_CR_PLS_1;   // PLS=110 → 2.8V
PWR->CR |= PWR_CR_PVDE;
EXTI->RTSR &= ~EXTI_RTSR_TR16;
EXTI->FTSR |= EXTI_FTSR_TR16;
EXTI->IMR |= EXTI_IMR_MR16;
NVIC_EnableIRQ(PVD_IRQn);

This PVD code is referenced in the note but does NOT exist in any of the 6 power project main.c files. It may be from a separate demo or the note's general reference material.

Summary

Overall Accuracy: Very High

Issues Found:

PVD code mentioned in note is NOT found in projects 15-20 main.c files — likely from separate reference material
SLEEP-ON-EXIT variant (SLEEPONEXIT=1) described in note but only SLEEP-NOW implemented in project 15
All other register/HAL low-power mode code matches actual files perfectly

Note 18 Power.md 4.0 KB تاريخچه خام