PM Example

Source path: example\rt_device\pm

Supported Platforms

The example can run on the following development boards.

  • sf32lb56-devkit-lcd_n16r12n1

  • eh-lb551

  • sf32lb52-lcd_n16r8

  • sf32lb58-lcd_n16r64n4

Overview

  • Demonstration of entering low power mode and waking up PM project under RT-Thread operating system

Example Usage

Compilation and Programming

sf32lb56-devkit-lcd_n16r12n1 compilation method

The 56 platform is configured by default for Standby Sleep mode
Compilation command

> scons --board=sf32lb56-devkit-lcd_n16r12n1 -j8

  • Switch to the example project/build_xx directory and run uart_download.bat, select the port as prompted (the serial port with print after pulling boot pin high) to download:

> build_sf32lb56-devkit-lcd_n16r12n1_hcpu\uart_download.bat

     Uart Download

please input the serial port num:5

eh-lb551 compilation method

The 56 platform is configured by default for Standby Sleep mode
Compilation command

> scons --board=eh-lb551 -j8

Confirm that Jlink is properly connected and can communicate successfully, as follows
alt text

  • Switch to the example project/build_xx directory. The 551 example currently only supports Jlink download, run download.bat to download

> build_eh-lb551_hcpu\download.bat

sf32lb52-lcd_n16r8 compilation method

Configure menuconfig for Deep Sleep mode

menuconfig

alt text The 52 platform recommends using Deep Sleep mode. Here change to Enable Deep Mode, save and exit

 → RTOS → RT-Thread Components → Device Drivers → Using Power Management device driverselect PM Mode

Compilation command

> scons --board=sf32lb52-lcd_n16r8 -j8

  • Switch to the example project/build_xx directory and run uart_download.bat, select the port as prompted to download:

> build_sf32lb52-lcd_n16r8_hcpu\uart_download.bat

     Uart Download

please input the serial port num:5

sf32lb58-lcd_n16r64n4 compilation method

The 56 platform is configured by default for Standby Sleep mode
Compilation command

> scons --board=sf32lb58-lcd_n16r64n4 -j8

  • Switch to the example project/build_sf32lb58-lcd_n16r64n4_hcpu directory and run download.bat, here demonstrating download via Jlink:

> build_sf32lb58-lcd_n16r64n4_hcpu\download.bat

  • sf32lb58-lcd_n16r64n4 board Jlink connection method is shown below:
    alt text

Hardware Connection

sf32lb56-devkit-lcd_n16r12n1

Use button PB32 on the board as wakeup PIN0#WKUP_PIN0, pressing the button changes the level high to wake up Hcpu

eh-lb551

Button KEY1PB48 on the board serves as Lcpu’s wakeup PIN5#WKUP_PIN5, pressing the button changes the level low to wake up Lcpu

sf32lb52-lcd_n16r8

Use button PA34 on the board as wakeup PIN10#WKUP_PIN10, pressing the button changes the level high to wake up Hcpu

sf32lb58-lcd_n16r64n4

Use button PB54 on the board as wakeup PIN0#WKUP_PIN0, pressing the button changes the level high to wake up Hcpu

Example Output Results

sf32lb56-devkit-lcd_n16r12n1

  • 566 hcpu log, entering standby

    Serial:c2,Chip:3,Package:1,Rev:2  Reason:00000000
    Serial PowerOnMOde:0 rtc_record:00000000
     \ | /
    - SiFli Corporation
     / | \     build on Apr 14 2025, 2.3.5 build aea79fd6
     2020 - 2022 Copyright by SiFli team
    [32;22m[I/FAL] Flash Abstraction Layer (V0.5.99) initialize success.[0m
    [32;22m[I/FAL] The FAL MTD NOR device (dfu) created successfully[0m
    [32;22m[I/FAL] The FAL MTD NOR device (ble) created successfully[0m
    [1701] I/drv.audprc main: init 00 ADC_PATH_CFG0 0x924
    [1723] I/drv.audprc main: HAL_AUDPRC_Init res 0
    [1744] I/drv.audcodec main: HAL_AUDCODEC_Init res 0
    [1765] I/TOUCH main: Regist touch screen driver, probe=1401f50d 
    call par CFG1(35bb)
    fc 9, xtal 2000, pll 2064
    call par CFG1(35bb)
    fc 7, xtal 2000, pll 1656
    mbox_stack:20007df0,1024
    proc_stack:200081f0,4096
    [1954] I/mw.sys ds_proc: turn on lcpu
    [139193] I/mw.sys ds_proc: rf ful ver:1.1.9_2841,calen:0xff
    hcpu main!!!
    msh >
    app_wakeup!
    SF32LB56X WER:0x1c4,WSR:0x0,CR1:0x80000002
    [pm]S:4,237566
    [pm]W:401728
    [pm]WSR:0x4
    hcpu timer wakeup!!!
    [pm]S:4,401761
    [pm]W:447328
    [pm]WSR:0x100
    hcpu timer wakeup!!!

  • 566 lcpu log(Lcpu project path is …/lcpu)

     \ | /
    - SiFli Corporation
     / | \     build on Jun 27 2022, 1.8.0 build cc1e38
     2020 - 2022 Copyright by SiFli team
    proc_stack:20403638,2048
    lcpu main!!!
    msh >
    [pm]S:4,237763
    [pm]W:401547
    [pm]WSR:0x60
    [pm]S:4,401801
    [pm]W:447147
    [pm]WSR:0x60

eh-lb551

  • 551 hcpu entering standby log

    Serial:c2,Chip:1,Package:0,Rev:80  Reason:00000000
    Serial PowerOnMOde:0 rtc_record:00000000
     \ | /
    - SiFli Corporation
     / | \     build on Apr 15 2025, 2.3.5 build aea79fd6
     2020 - 2022 Copyright by SiFli team
    [32;22m[I/FAL] Flash Abstraction Layer (V0.5.99) initialize success.[0m
    [32;22m[I/FAL] The FAL MTD NOR device (dfu) created successfully[0m
    [32;22m[I/FAL] The FAL MTD NOR device (ble) created successfully[0m
    [299] I/drv.rtc main: PSCLR=0x80000100 DivAI=128 DivAF=0 B=256
    [306] I/drv.rtc main: RC10K Freq=9kHz, cycle=985648, rtc ppm=0
    [314] I/drv.rtc main: DIVA=38, DIVA_FRA=754, DIVB=256
    [320] I/drv.rtc main: Init RTC, wake = 0
    [371] I/TOUCH main: Regist touch screen driver, probe=1003ef3d 
    mbox_stack:20000000,1024
    proc_stack:20000400,4096
    [389] I/mw.sys ds_proc: turn on lcpu
    [535] I/mw.sys ds_proc: rf ful ver:null,calen:0xff
    hcpu main!!!
    msh >
    [pm]S:4,29758
    [pm]W:78662
    [pm]WSR:0x2
    hcpu timer wakeup!!!
    [pm]S:4,78672

  • 551 log for entering hibernate after booting when Hcpu hasn’t slept yet using serial command sleep down and button wakeup Since eh-lb551 board doesn’t have 32768 crystal by default, the macro LXT_DISABLE is enabled, so after entering Hibernate and waking up with button, there is no PM_HIBERNATE_BOOT flag

   Serial:c2,Chip:1,Package:0,Rev:80  Reason:00000000
   Serial PowerOnMOde:0 rtc_record:00000000
    \ | /
   - SiFli Corporation
    / | \     build on Apr 15 2025, 2.3.5 build aea79fd6
    2020 - 2022 Copyright by SiFli team
   [32;22m[I/FAL] Flash Abstraction Layer (V0.5.99) initialize success.[0m
   [32;22m[I/FAL] The FAL MTD NOR device (dfu) created successfully[0m
   [32;22m[I/FAL] The FAL MTD NOR device (ble) created successfully[0m
   [299] I/drv.rtc main: PSCLR=0x80000100 DivAI=128 DivAF=0 B=256
   [306] I/drv.rtc main: RC10K Freq=9kHz, cycle=985621, rtc ppm=0
   [314] I/drv.rtc main: DIVA=38, DIVA_FRA=771, DIVB=256
   [320] I/drv.rtc main: Init RTC, wake = 0
   [371] I/TOUCH main: Regist touch screen driver, probe=1003ef3d 
   mbox_stack:20000000,1024
   proc_stack:20000400,4096
   [389] I/mw.sys ds_proc: turn on lcpu
   [534] I/mw.sys ds_proc: rf ful ver:null,calen:0xff
   hcpu main!!!
   msh >
TX:sleep down
   sleep down
   SF32LB55X entry_hibernate
   SF32LB55X CR:0x180000,WER:0x200
   Serial:c2,Chip:1,Package:0,Rev:80  Reason:00000000
   Serial PowerOnMOde:3 rtc_record:00000000
   [32;22m[I/FAL] Flash Abstraction Layer (V0.5.99) initialize success.[0m
   [32;22m[I/FAL] The FAL MTD NOR device (dfu) created successfully[0m
   [32;22m[I/FAL] The FAL MTD NOR device (ble) created successfully[0m
   [285] I/drv.rtc main: PSCLR=0x260c0d00 DivAI=38 DivAF=771 B=256
   [293] I/drv.rtc main: RC10K Freq=9kHz, cycle=985733, rtc ppm=0
   [300] I/drv.rtc main: DIVA=38, DIVA_FRA=701, DIVB=256
   [306] I/drv.rtc main: Init RTC, wake = 1
   [313] I/TOUCH main: Regist touch screen driver, probe=1003ef3d 
   mbox_stack:20000000,1024
   proc_stack:20000400,4096
   [332] I/mw.sys ds_proc: turn on lcpu
   [477] I/mw.sys ds_proc: rf ful ver:null,calen:0xff
   hcpu main!!!
   msh >

  • 551 lcpu log including entering standby, entering hibernate and button wakeup log(Lcpu project path is …/lcpu)

    \ | /
   - SiFli Corporation
    / | \     build Jul 21 2021, 0.9.5.6
    2020 - 2021 Copyright by SiFli team
   proc_stack:20105ba4,2048
   lcpu main!!!
   msh >
   [pm]S:4,29794
   [pm]W:78613
   [pm]WSR:0x810
   [pm]S:4,78693
   [pm]W:89639
   [pm]WSR:0x410
   Lcpu wake_key_handle!!!
   [pm]S:4,89655
   [pm]W:90930
   [pm]WSR:0x410
   Lcpu wake_key_handle!!!
   [pm]S:4,90946

sf32lb52-lcd_n16r8

  • sf32lb52-lcd_n16r8 running log output

   SFBL
   Serial:c2,Chip:4,Package:3,Rev:3  Reason:00000000
   Serial PowerOnMOde:0 rtc_record:00000000
    \ | /
   - SiFli Corporation
    / | \     build on Jan  8 2025, 2.2.4 build 00000000
    2020 - 2022 Copyright by SiFli team
   [32;22m[I/FAL] Flash Abstraction Layer (V0.5.99) initialize success.[0m
   [32;22m[I/FAL] The FAL MTD NOR device (dfu) created successfully[0m
   [32;22m[I/FAL] The FAL MTD NOR device (ble) created successfully[0m
   [573] I/drv.rtc main: PSCLR=0x80000100 DivAI=128 DivAF=0 B=256
   [599] I/drv.rtc main: RTC use LXT RTC_CR=00000001
   [619] I/drv.rtc main: Init RTC, wake = 1
   [645] I/drv.audprc main: init 00 ADC_PATH_CFG0 0x606
   [665] I/drv.audprc main: HAL_AUDPRC_Init res 0
   [686] I/drv.audcodec main: HAL_AUDCODEC_Init res 0
   [706] I/TOUCH main: Regist touch screen driver, probe=1203e225 
   call par CFG1(35bb)
   fc 9, xtal 2000, pll 2054
   call par CFG1(35bb)
   fc 9, xtal 2000, pll 2053
   mbox_stack:200067f8,1024
   proc_stack:20006bf8,4096
   [937] I/mw.sys ds_proc: turn on lcpu
   [36981] I/mw.sys ds_proc: rf ful ver:1.1.13_2859,calen:0xf
   hcpu main!!!
   msh >
   [pm]S:3,135137
   [pm]W:298069
   [pm]WSR:0x40002
   gpio_wakeup_handler!
   hcpu timer wakeup!!!
   [pm]S:3,298998
   [pm]W:462858
   [pm]WSR:0x4
   hcpu timer wakeup!!!
   [pm]S:3,462881

  • sf32lb52-lcd_n16r8 entering hibernate and button wakeup log

    SFBL
    Serial:c2,Chip:4,Package:3,Rev:3  Reason:00000000
    Serial PowerOnMOde:0 rtc_record:00000000
     \ | /
    - SiFli Corporation
     / | \     build on Jan  8 2025, 2.2.4 build 00000000
     2020 - 2022 Copyright by SiFli team
    [32;22m[I/FAL] Flash Abstraction Layer (V0.5.99) initialize success.[0m
    [32;22m[I/FAL] The FAL MTD NOR device (dfu) created successfully[0m
    [32;22m[I/FAL] The FAL MTD NOR device (ble) created successfully[0m
    [585] I/drv.rtc main: PSCLR=0x80000100 DivAI=128 DivAF=0 B=256
    [611] I/drv.rtc main: RTC use LXT RTC_CR=00000001
    [631] I/drv.rtc main: Init RTC, wake = 1
    [658] I/drv.audprc main: init 00 ADC_PATH_CFG0 0x606
    [678] I/drv.audprc main: HAL_AUDPRC_Init res 0
    [699] I/drv.audcodec main: HAL_AUDCODEC_Init res 0
    [719] I/TOUCH main: Regist touch screen driver, probe=1203e245 
    call par CFG1(35bb)
    fc 9, xtal 2000, pll 2056
    call par CFG1(35bb)
    fc 7, xtal 2000, pll 1646
    mbox_stack:200067f8,1024
    proc_stack:20006bf8,4096
    [950] I/mw.sys ds_proc: turn on lcpu
    [36961] I/mw.sys ds_proc: rf ful ver:1.1.13_2859,calen:0xf
    hcpu main!!!
    msh >
 TX:sleep down
    sleep down
    SF32LB52X entry_hibernate
    SF32LB52X CR:0xa801,WER:0x8c
    SFBL
    Serial:c2,Chip:4,Package:3,Rev:3  Reason:00000000
    Serial PowerOnMOde:2 rtc_record:00000000
    [32;22m[I/FAL] Flash Abstraction Layer (V0.5.99) initialize success.[0m
    [32;22m[I/FAL] The FAL MTD NOR device (dfu) created successfully[0m
    [32;22m[I/FAL] The FAL MTD NOR device (ble) created successfully[0m
    [505] I/drv.rtc main: PSCLR=0x80000100 DivAI=128 DivAF=0 B=256
    [530] I/drv.rtc main: RTC use LXT RTC_CR=00000001
    [550] I/drv.rtc main: Init RTC, wake = 1
    [576] I/drv.audprc main: init 00 ADC_PATH_CFG0 0x606
    [597] I/drv.audprc main: HAL_AUDPRC_Init res 0
    [617] I/drv.audcodec main: HAL_AUDCODEC_Init res 0
    [638] I/TOUCH main: Regist touch screen driver, probe=1203e245 
    call par CFG1(35bb)
    fc 9, xtal 2000, pll 2058
    call par CFG1(35bb)
    fc 7, xtal 2000, pll 1645
    mbox_stack:200067f8,1024
    proc_stack:20006bf8,4096
    [869] I/mw.sys ds_proc: turn on lcpu
    [36944] I/mw.sys ds_proc: rf ful ver:1.1.13_2859,calen:0xf
    hcpu main!!!
    msh >
    boot from hibernate!!!
    [pm]S:3,135216

sf32lb58-lcd_n16r64n4

  • sf32lb58-lcd_n16r64n4 hcpu running log output, including entering standby, PB54 button wakeup log

 Serial:c2,Chip:2,Package:0,Rev:1  Reason:00000000
 Serial PowerOnMOde:0 rtc_record:00000000
  \ | /
 - SiFli Corporation
  / | \     build on Jan 24 2025, 2.3.0 build 00000000
  2020 - 2022 Copyright by SiFli team
 [32;22m[I/FAL] Flash Abstraction Layer (V0.5.99) initialize success.[0m
 [31;22m[E/FAL] (fal_mtd_nor_device_create:496) Error: the flash device name (flash3) is not found.[0m
 [31;22m[E/FAL] (fal_mtd_nor_device_create:496) Error: the flash device name (flash3) is not found.[0m
 [D/USBD] No class register on usb device
 [1191] I/drv.rtc main: PSCLR=0x80000100 DivAI=128 DivAF=0 B=256
 [1215] I/drv.rtc main: RTC use LXT RTC_CR=00000000
 [1235] I/drv.rtc main: Init RTC, wake = 0
 [1397] I/drv.audprc main: init 00 ADC_PATH_CFG0 0x924
 [1418] I/drv.audprc main: HAL_AUDPRC_Init res 0
 [1437] I/drv.audcodec main: HAL_AUDCODEC_Init res 0
 [1458] I/TOUCH main: Regist touch screen driver, probe=10023e9d 
 call par CFG1(35bb)
 fc 11, xtal 2000, pll 1985
 call par CFG1(35bb)
 fc 9, xtal 2000, pll 1984
 mbox_stack:20000000,1024
 proc_stack:20000400,4096
 [1639] I/mw.sys ds_proc: turn on lcpu
 [47036] I/mw.sys ds_proc: rf ful ver:1.0.0.1,calen:0xff
 hcpu main!!!
 msh >
 SF32LB58X AON CR1:0x80000000,CR2:0x0,WER:0x1c4
 [pm]S:4,145384
 [pm]W:198520
 [pm]WSR:0x100
 gpio_wakeup_handler!
 [pm]S:4,205008
 [pm]W:309478
 [pm]WSR:0x4
 hcpu timer wakeup!!!
 [pm]S:4,309501

  • sf32lb58-lcd_n16r64n4 lcpu running log output, including entering standby, PB54 button wakeup log

 \ | /
- SiFli Corporation
 / | \     build on Mar 20 2022, 1.2.0 build dbebac
 2020 - 2022 Copyright by SiFli team
proc_stack:2040759c,2048
lcpu main!!!
msh >
[pm]S:4,145530
[pm]W:177325
[pm]WSR:0x60
[pm]S:4,185126
[pm]W:309339
[pm]WSR:0x60
[pm]S:4,309537

  • sf32lb58-lcd_n16r64n4 hcpu receiving command sleep down via serial port to enter hibernate and wake up with PB54 button log

    Serial:c2,Chip:2,Package:0,Rev:1  Reason:00000000
    Serial PowerOnMOde:0 rtc_record:00000000
     \ | /
    - SiFli Corporation
     / | \     build on Jan 24 2025, 2.3.0 build 00000000
     2020 - 2022 Copyright by SiFli team
    [32;22m[I/FAL] Flash Abstraction Layer (V0.5.99) initialize success.[0m
    [31;22m[E/FAL] (fal_mtd_nor_device_create:496) Error: the flash device name (flash3) is not found.[0m
    [31;22m[E/FAL] (fal_mtd_nor_device_create:496) Error: the flash device name (flash3) is not found.[0m
    [D/USBD] No class register on usb device
    [1192] I/drv.rtc main: PSCLR=0x80000100 DivAI=128 DivAF=0 B=256
    [1216] I/drv.rtc main: RTC use LXT RTC_CR=00000000
    [1235] I/drv.rtc main: Init RTC, wake = 0
    [1397] I/drv.audprc main: init 00 ADC_PATH_CFG0 0x924
    [1418] I/drv.audprc main: HAL_AUDPRC_Init res 0
    [1437] I/drv.audcodec main: HAL_AUDCODEC_Init res 0
    [1458] I/TOUCH main: Regist touch screen driver, probe=10023e9d 
    call par CFG1(35bb)
    fc 11, xtal 2000, pll 1986
    call par CFG1(35bb)
    fc 9, xtal 2000, pll 1986
    mbox_stack:20000000,1024
    proc_stack:20000400,4096
    [1639] I/mw.sys ds_proc: turn on lcpu
    [47034] I/mw.sys ds_proc: rf ful ver:1.0.0.1,calen:0xff
    hcpu main!!!
    msh >
 TX:sleep down
    sleep down
    SF32LB58X entry_hibernate
    SF32LB5XX CR:0x4001,WER:0x8,WKUP_CNT:0x10001,PBR0R:0x800002a7
    Serial:c2,Chip:2,Package:0,Rev:1  Reason:00000000
    Serial PowerOnMOde:2 rtc_record:00000000
    [32;22m[I/FAL] Flash Abstraction Layer (V0.5.99) initialize success.[0m
    [31;22m[E/FAL] (fal_mtd_nor_device_create:496) Error: the flash device name (flash3) is not found.[0m
    [31;22m[E/FAL] (fal_mtd_nor_device_create:496) Error: the flash device name (flash3) is not found.[0m
    [D/USBD] No class register on usb device
    [286] I/drv.rtc main: PSCLR=0x80000100 DivAI=128 DivAF=0 B=256
    [310] I/drv.rtc main: RTC use LXT RTC_CR=00000000
    [329] I/drv.rtc main: Init RTC, wake = 1
    [357] I/drv.audprc main: init 00 ADC_PATH_CFG0 0x924
    [377] I/drv.audprc main: HAL_AUDPRC_Init res 0
    [396] I/drv.audcodec main: HAL_AUDCODEC_Init res 0
    [416] I/TOUCH main: Regist touch screen driver, probe=10023e9d 
    call par CFG1(35bb)
    fc 11, xtal 2000, pll 1984
    call par CFG1(35bb)
    fc 9, xtal 2000, pll 1985
    mbox_stack:20000000,1024
    proc_stack:20000400,4096
    [598] I/mw.sys ds_proc: turn on lcpu
    [46091] I/mw.sys ds_proc: rf ful ver:1.0.0.1,calen:0xff
    hcpu main!!!
    msh >
    SF32LB58X AON CR1:0x80000000,CR2:0x0,WER:0x1c4
    boot from hibernate!!!
    [pm]S:4,144433
    [pm]W:308543
    [pm]WSR:0x4
    hcpu timer wakeup!!!
    [pm]S:4,308566

Sleep Flow

sf32lb56-devkit-lcd_n16r12n1

  • hcpu sleep wakeup
    When hcpu enters the idle thread and determines whether sleep conditions are met, it will sleep and wake up according to the following flow
    rt_thread_idle_entry->rt_system_power_manager->_pm_enter_sleep->’pm->ops->sleep(pm, mode);->sifli_sleep -> log print [pm]S:4,11620140 -> RT_DEVICE_CTRL_SUSPEND device suspend -> sifli_standby_handler ->BSP_IO_Power_Down-> assembly WFI enter standby-> timer or IO wakeup -> function SystemInitFromStandby -> HAL_Init -> BSP_IO_Init-> restore_context-> PC pointer set to continue running from instruction after WFI in sifli_standby_handler function -> BSP_Power_Up-> execute RTT device RT_DEVICE_CTRL_RESUME device resume function -> log print [pm]W:11620520 -> log print [pm]WSR:0x80

  • LCPU sleep wakeup
    Lcpu sleep wakeup flow is basically the same as hcpu standby flow, difference: sifli_standby_handler-> sifli_standby_handler_core->IO configuration function during sleep BSP_IO_Power_Down->memory sleep function soc_power_down-> assembly WFI enter standby->timer or IO wakeup -> function SystemPowerOnModeInit ->SystemPowerOnInitLCPU-> HAL_Init-> BSP_IO_Init-> restore_context-> set to continue execution after WFI instruction -> memory exit sleep function soc_power_up-> IO configuration function after sleep BSP_Power_Up-> execute RTT device RT_DEVICE_CTRL_RESUME device resume function -> log print [pm]W:11620520 -> log print [pm]WSR:0x80

eh-lb551

  • hcpu sleep wakeup
    55 series has the same standby flow as 56 series, difference is in the wakeup function
    timer or IO wakeup -> function SystemPowerOnModeInit -> HAL_Init -> BSP_IO_Init->restore_context-> PC pointer set to continue running from instruction after WFI in sifli_standby_handler function -> BSP_Power_Up-> execute RTT device RT_DEVICE_CTRL_RESUME device resume function -> log print [pm]W:11620520 -> log print [pm]WSR:0x80

  • LCPU sleep wakeup
    Lcpu wakeup flow is the same as 56 series

sf32lb52-lcd_n16r8

  • hcpu sleep wakeup
    52 series differs from 56 series standby flow in that it enters sifli_deep_handler(); standby function, and lacks peripheral SUSPEND/RESUME and context recovery process, making sleep wakeup faster
    sifli_sleep -> log print [pm]S:3,11620140 -> sifli_deep_handler ->BSP_IO_Power_Down-> assembly WFI enter deep-> timer or IO wakeup -> continue running from instruction after WFI -> BSP_Power_Up-> log print [pm]W:11620520 -> log print [pm]WSR:0x80

  • LCPU sleep wakeup
    52 series Lcpu code is not open for modification, this part doesn’t need consideration

sf32lb58-lcd_n16r64n4

  • hcpu sleep wakeup
    58 series has the same standby flow as 56 series

  • LCPU sleep wakeup
    Lcpu wakeup flow is the same as 56 series

Hibernate Flow

  • Entering Hibernate
    Entering Hibernate flow is relatively simple, all call function HAL_PMU_EnterHibernate();. Before the chip sleeps, it needs to configure the PMU wakeup PIN and wakeup level after Hibernate. For 55 series MCU, all wakeup PINs are floating input under hibernate, external circuits need to provide pull-up/down states, no other processing needed. For 58, 56, 52 series MCU, since wakeup PINs have an additional set of PMU pull-up/down system effective under Hibernate, to avoid leakage, you can use function HAL_PIN_Set to configure wakeup PIN pull-up/down. For 52 series MCU, since it has 3 built-in LDOs, you need to check your hardware connection to consider whether to configure shutdown through function HAL_PMU_ConfigPeriLdo
    The hwp_pmuc->WKUP_CNT register can configure how long the external signal needs to persist under hibernate to wake up (only for 58, 56, 52 series MCU);
    Note:
    For 55 series MCU, since each wakeup pin can be enabled individually, configuring Hibernate wakeup source only needs to call function HAL_PMU_EnablePinWakeup to enable the corresponding wakeup pin;
    For 58, 56, 52 series MCU, only 2 wakeup sources pin0, pin1 are allowed simultaneously. Here an additional step is needed, call function HAL_PMU_SelectWakeupPin to configure which specific wakeup pin corresponds to pin0 and pin1, corresponding register configuration refer to hwp_pmuc->CR;

  • Hibernate wakeup
    After pressing wakeup PIN to wake up from Hibernate, you can judge (PM_HIBERNATE_BOOT == SystemPowerOnModeGet()) whether it is hibernate boot and the button press duration to determine whether to boot
    The log print boot from hibernate!!! can indicate boot from hibernate

Exception Diagnosis

Wakeup Log Interpretation

   [pm]S:3,298998<br>
    S indicates entered sleep, 3 indicates sleep mode is PM_SLEEP_MODE_DEEP, 4 represents PM_SLEEP_MODE_STANDBY, 298998 is Gtimer timestamp<br>
   [pm]W:462858 <br>
   W indicates woken up, 462858 is Gtimer timestamp<br>
   [pm]WSR:0x4 <br>
   WSR is wakeup register, 0x04 is WSR register value, need to refer to specification to check which wakeup source<br>

No PM[S] print

Reason 1:
Confirm the following macros are enabled

#define RT_USING_PM 1
#define PM_STANDBY_ENABLE 1 //#define PM_DEEP_ENABLE 1 //525 is Deep
#define BSP_USING_PM 1
#define BSP_PM_DEBUG 1

Reason 2:
Software didn’t enter sifli_sleep function
When hcpu is not busy, it will enter idle thread, and when sleep conditions are met, it will enter sleep sifli_sleep function according to the following flow
rt_thread_idle_entry->rt_system_power_manager->_pm_enter_sleep->’pm->ops->sleep(pm, mode);->sifli_sleep -> log print [pm]S:4,11620140
In _pm_enter_sleep function, it will judge whether sleep conditions are met, only enter sleep when met. For how each sleep condition is judged, refer to FAQ document low power section and low power development guide

No [pm]W print

Reason 1:
If there is already PM[S] print, and there are timer wakeups, but no [pm]W print, usually there is a crash during sleep or wakeup process. Common reasons include adding prints (serial port is suspended and unusable at this time) in BSP_IO_Power_Down, BSP_PIN_Init function or peripheral RT_DEVICE_CTRL_SUSPEND message, or operating the other core’s GPIO registers (when Hcpu is standby, Lcpu is allowed to sleep, and Lcpu cannot operate PA port);
As shown below, the most common crash is operating PA port outside the macro #ifdef SOC_BF0_HCPU in the shared function BSP_PIN_Init for Hcpu and Lcpu. Since Lcpu cannot operate PA port, it causes crash after standby wakeup
alt text Crashes at this time are difficult to debug, Jlink and serial port may no longer work. The usual method is to use instruction __asm("B .") to stop the CPU at places where MCU is confirmed to still run normally with Jlink or serial port, may also need to disable interrupts (if not disabled, OS is running and will switch to other threads). If crash is suspected during sleep process, can stop after [pm]S:3,298998 print. If crash is suspected after wakeup, hcpu can use B . to stop MCU at the beginning of Reset_Handler in startup_bf0_hcpu.S, Lcpu can use it in startup_bf0_lcpu.S, then use Jlink single-step to find the crash point;

No button wakeup after Standby

Reason 1:
Hcpu can compare WER, CR register values of HPSYS_AON at this time, Lcpu can compare WER, CR register values of LPSYS_AON at this time, check if corresponding wakeup PIN and wakeup mode are configured correctly, below shows 52 specification as example
alt text alt text Note: There are many ways to read register values at this time, including printing register values, Jlink, serial port read/write, not repeated here, refer to FAQ development tools section

55 series MCU Lcpu no log print

For 55 series MCU, to solve Lcpu RAM shortage, production chips upgraded from A0 to A3 version. A3 version chips have more code in ROM, thus freeing up more usable RAM space. In SDK code, need to configure corresponding to chip, as shown below rtconfig.h positioning flag for A3 version

#define BSP_LB55X_CHIP_ID 3

Chip version check can look at chip bottom marking, for example: TFA2XXXXX represents A2 version chip (using default configuration Lcpu will crash, no log output), default example is verified on TFA3XXXXX(A3) version chip;
If changing to A2 version configuration, both Hcpu and Lcpu rtconfig.h need to modify #define BSP_LB55X_CHIP_ID 2

No button wakeup after Hibernate

Reason 1:
The example adds finsh command to enter hibernate, Hcpu serial input sleep down can enter hibernate shutdown state
After Hibernate shutdown, unlike Standby wakeup which can resume to original program, waking up from Hibernate is equivalent to cold start (but has PM_HIBERNATE_BOOT flag), wakeup PIN and level mode are controlled by PMU registers
Whether related configuration is effective, can print corresponding PMU WER, CR register values to compare, below shows 52 specification as example

rt_kprintf("SF32LB52X CR:0x%x,WER:0x%x\n",hwp_pmuc->CR,hwp_pmuc->WER);

alt text Reason 2:
Configured wrong wakeup PIN or wakeup level, for example 55 series MCU, under Hibernate, only Lcpu wakeup PIN0-5 have specific wakeup function, specifically check 55 series user manual PMUC WER register configuration
For 58, 56, 52 series MCU, only two wakeup sources PIN0 and PIN1 are allowed simultaneously, each wakeup source can be assigned to any Hcpu/Lcpu wakeup PIN, specific configuration check user manual PMUC CR register configuration
Note:
For 55 series MCU, when system is in hibernate mode, PA77-80 cannot be used for boot wakeup.
For 55 series MCU, when system is in hibernate mode, PB43-48 can be used for boot wakeup.

Automatic restart immediately after Hibernate

Reason 1:
Wakeup PIN level configuration error, after entering Hibernate, external level conditions are met, wake up immediately
Reason 2:
After entering Hibernate, didn’t disable interrupts and add while(1); wait. Since entering Hibernate takes time, without disabling interrupts and infinite loop, code will continue running

No PM_HIBERNATE_BOOT flag after Hibernate button wakeup

The difference between hibernate mode and powerdown mode is that RTC 32768 clock is still running under hibernate mode, but some customers for cost considerations don’t install 32768 crystal, need to enable macro LXT_DISABLE, after enabling 32768 clock will not run

#define LXT_DISABLE 1

In this case, entering hibernate mode, even if 32768 crystal is installed, actually there is no RTC clock running. After entering Hibernate and waking up with button, there will be no PM_HIBERNATE_BOOT flag. Boot wakeup in this example will not see log: boot from hibernate!!!

Reference Documentation

  • EH-SF32LB52X_Pin_config_V1.3.0_20231110.xlsx

  • DS0052-SF32LB52x-Chip Technical Specification V0p3.pdf

  • UM0052-SF32LB52x-User Manual V0p5.pdf

  • UM0055-SF32LB55x-User Manual V0p1.pdf

  • UM0056-SF32LB56x-User Manual V0p7.pdf

  • AN0003-SF32LB55x-Low Power Development Guide V0p5.pdf

  • SF32LB5XX-FAQ-V0.04.pdf

  • RT-Thread Official Website
    https://www.rt-thread.org/document/site/#/rt-thread-version/rt-thread-standard/programming-manual/pm/pm

Update Log

Version

Date

Release Notes

0.0.2

01/2025

Initial version