djsundog/circuitpython
1
0
Fork 0
Code Issues Pull Requests Packages Projects Releases Wiki Activity

stm32/powerctrl: Disable RTC write protection before changing flags.

Browse Source
This commit is contained in:
iabdalkader 2020-12-02 23:35:58 +02:00 committed by Damien George
parent 463a275bc4
commit 8add94e94e
1 changed files with 7 additions and 0 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

7
ports/stm32/powerctrl.c
View File

@ -689,6 +689,10 @@ void powerctrl_enter_standby_mode(void) {
// save RTC interrupts
uint32_t save_irq_bits = RTC->CR & CR_BITS;
// disable register write protection
RTC->WPR = 0xca;
RTC->WPR = 0x53;
// disable RTC interrupts
RTC->CR &= ~CR_BITS;
@ -714,6 +718,9 @@ void powerctrl_enter_standby_mode(void) {
// enable previously-enabled RTC interrupts
RTC->CR |= save_irq_bits;
// enable register write protection
RTC->WPR = 0xff;
#if defined(STM32F7)
// Enable the internal (eg RTC) wakeup sources
// See Errata 2.2.2 "Wakeup from Standby mode when the back-up SRAM regulator is enabled"