Power Down Reset Stm32Otherwise, press the RESET button on your STM32 board. The STM32 board can be turn on by using the 3. From software point of view, hot reset has same effect to warm reset. STM32F10x: Low power In standby mode, current consumption is as low as 2 µA typical, with reset circuitry active. Tap or select Shut down or sign out and choose Shut down. Usually, you should not connect the nTRST and nSRST lines. They are connected between ground and the appropriate pin on a device. June 2017 DocID028794 Rev 4 1/224 STM32L433xx Ultra-low-power ARM® Cortex®-M4 32-bit MCU+FPU, 100DMIPS, up to 256KB Flash, 64KB SRAM, USB FS, LCD, ext. In this post, I will explore entering and exiting the 3 low power or power saving modes available on stm32f030 micro controller. After that, STM32 sends the disable signal to the regulator who provides the power to the whole system. LD3 is a power LED for 5V supply. The device can be waked up by using the timer overflow. The microcontroller operates at 3. • On STM32L0 devices operating at 1. Software reset, backup area reset can be generated by setting . a Blue Pill is a Development board for the ARM Cortex M3 Microcontroller. Peek at the Assembly Code generated by the compiler, as well as the Vector Map and reset_handler () used during Blue Pill startup. I do not see the reset line change when I OCD. The RCC CSR register stores reset indications, and you can know the resend of resembling, source: Directly provide functions for system reset directly in the corn_cm3. Whether you use UART to program the STM32, you will need to move the jumper on the board that marked as Boot0 from 0 to 1, and maintain the Boot1 jumper as 0. Input and Output data registers. Basically, you can write GPIO codes in multiple ways (Using HAL, GPIO driver). The purpose of introducing this difference is to prevent the voltage from jittering slightly above and below the threshold, and frequent interruptions. Right as the STM32 powered on, I was then enabling the SPI -> RF device, which was tied to the STM32 interrupt driven. Taobao sellers offer these starting from $1. To prevent stm32 microcontroller from any power related issues like power on reset and other potential errors buzzer is interfaced with transistor. Raspberry Pi Reset/shutdown button. There is no Schottky diode between USB +5V and system VIN power. Key features of the STM32 embedded RTC are highlighted below: Programmable Prescaler: division factor up to. All internal reset sources provide a reset signal on the NRST pin, which can be used to reset other components of the application board. A reset on the STM32 microcontroller can be forced from: the internal watchdogs, a software reset via the NVIC, the internal Power on reset/Power down reset . Voltage Regulator는 항상 Reset 후에 동작함. Assertion failed: jtag_trst == 0, file src/jtag/core. The Power Management HAT is a smart power bank designed for Raspberry Pi. • The brownout reset (BOR) circuitry must be disabled. Power-on/power-down reset (POR/PDR . 6 V Power-on/Power-down reset (POR/PDR) Programmable Brownout reset (BOR) Programmable voltage detector (PVD) Low-power modes:Sleep, Stop, Standby, Shutdown VBAT supply for RTC and backup registers Clock management 4 to 48 MHz crystal oscillator 32 kHz crystal oscillator with calibration. arm-none-eabi-objdump -h -S ST-2100. It is always active, and ensures proper operation starting from/down to 2 V. Reset should be connected to 3. The device operates on a single 2. In Run mode, the CPU is clocked by HCLK and the program code is executed. This is my first time to design STM32 circuit and I have no experience about the power down procedure. Interestingly enough, the STM32 seems to support autobaud detection by default. Analyze the reasons: In addition to the power-on and power-down reset of STM32, most STM32s also have a brown-out reset. One of the differences between Maple Mini and Blue Pill is that the +5V pins on Blue Pill is directly connected to the +5V pin of the USB connector. Your temperature control system might want to function locally despite power loss. 6V, the BOR can be disabled by option bytes. it is example for calendar using STM32 series Reset of all peripherals, Initializes the Flash interface and the . ESP32 RTC time is preserved during deepsleep, and you can wake up after defined time, by external pin, by touch event, or by any activity which can be handled by ULP. Onboard Mini USB interface, you can give the board power supply and USB communication. How long (in milliseconds) OpenOCD should wait after deasserting nSRST. A non-running clock will prevent you from connecting AFAIK. It has multiple modules within itself which allows the user to communicate and design the interface of different kinds without relying on any third device. STM32: Get reset source, software reset. I have designed many boards with STM32 chips as well as other MCU's. When the power supply is turned off the voltage does not go all the way down. There is no dedicated USB reset circuitry on this board. Re: STM32-E407 OpenOCD with ARM-USB-OCD. According to different models and available resources, xx can be divided into: The contents of different startup files are similar. a hardware mechanism for setting or returning all hardware states to the initial conditions. Hands-on technical pre-requisites: - PC with admin rights running Windows 7 or higher - STM32 discovery kit 32L476GDISCOVERY . Low power bus powered functions draw all its power from the V BUS and cannot draw any more than one unit load. This supply is used to power the internal digital circuits (after being sub-regulated down to 1. This blog post clearly describes how to achieve this. The STM32F4 Discovery board is small devices based on STMF407 ARM microcontroller, which is a high-performance microcontroller. Description The STM32 Nucleo board provides an affordable and flexible way for users to try out new ideas and build prototypes with any STM32 microcontroller line, choosing from the various combinations of performance, power consumption and features. Enough USB support to be able to enumerate the device and use bulk or interrupt endpoints. To enter into the power-save mode we need to write the SM [2,0] pin to '011'. Program will automatically start with downloading data to STM32F4. reset_cause_t reset_cause = reset_cause_get (); printf ("The system reset cause is \"%s\"\n", reset_cause_get_name (reset_cause)); Output: The system reset cause is "INDEPENDENT_WATCHDOG_RESET". Now to bring the Blue pill back to normal mode make sure you bring the BOOT jumper back at its place. speed, the STM32 has a current consumption as low as 27 mA. Here is a step by step guide to setting up a Open Source Stm32 Arm based embedded development tool chain with the Eclipse IDE. the end of calibration is indicated by the CAL flag going low. Oscillator startup time effects on POR delay d. System Power-Up Sequence As the MCU begins to experience a rising voltage on its V DD pin, several things begin to happen: • Once VDD reaches a level sufficient for the CMOS logic to begin. Board also support multiple resets. People who use low-power modes will get bitten at least once by this. The next command, flash write_image erase p:/tmp/blink. The project will be set up to use the Arm CMSIS Library which provides a common. Do not connect 5V between programmer and STM32 if you are supplying voltage via USB as STM32 Blue Pill does not have power protection circuitry and this will damage your STM32 Blue Pill. Reset button; LED on PIN PC13; 32 kHz Real time clock crystal; Jump links on Boot0 and Boot1; Micro USB connector for power and data; ST-Link header on the top of the board. A voltage supervisor (also known as a reset integrated circuit [IC]) is a type of voltage monitor that monitors a system's power supply. ADS1299 bootup procedure for STM32 HAL. Power-on reset (POR), power-down reset (PDR) and programmable voltage detector (PVD). The Led pin Pc-13 is declared as output and button Pa-10 as input. Leave other settings as they are. This is a second release of the soldering iron controller for Hakko T12 tips based on STM32 micro controller. 5K resistor EACH next to the hot swap sockets, like shown in picture. I have commented the MX_RTC_Init () in the startup, so that RTC is not reset when the MCU restart. The device remains in reset mode when VDD is below a specified threshold, VPOR/PDR, without the need for an external reset circuit. Most timers will "roll over" once they reach their max value. powerDown (SLEEP_8S, ADC_OFF, BOD_OFF); The code is used to turn on the power-down mode. Here is the simplified block diagram of the system reset. Press and release the Reset button while continuing to press the Boot button. There is no BOR to detect this condition and cause a reset. You can also write a wrapper for the specific function that is causing the reset. STM32 have Several low power modes are available to save power, when the CPU does not need to be kept running, for example when waiting for an external event. In addition, no external reset circuitry is needed due to the internal glitch filter and the safe power monitoring feature which guarantees the. Just note that each mode requires you to set a few registers and it will automatically enter that low power mode once you call WFI or WFE functions later. 6 V power supply enables its use for battery operated applications. A voltage supervisor (also known as a reset integrated voltage supervisors that asserts a reset output if the. The STM32 allows you to address bits individually with the BSRR. void SystemClock_Config (void). The problem is I can shut down the I2C modules but cannor restart them again. Immediately, the onboard LED will start blinking. A voltage supervisor (also known as a reset integrated circuit [IC]) is a type of voltage monitor that monitors a system’s power supply. It is Targeted for the ST32-Discovery demo board under Windows (This was implemented under Windows 7 64bit) and uses the open source Code Sourcery version of the Gnu Arm cross assembler. We're starting to investigate zephyr power management support for STM32, with a first focus on STM32WB. 4 to 48 MHz crystal oscillator; 32 kHz crystal oscillator with calibration. This provides a low-latency direct path to change the state of outputs or to read the state of inputs. Code::Blocks is a free IDE for C and C++. The STM32 has programmable BOR thresholds, which defaults to 1. The ADC peripheral on the STM32 processor is a flexible but complex beast. Disconnect the power adapter and depress this button with a paper-clip or similar item. The STM32's SPI peripheral resets to a convenient state for simple communication, but there are still a few options that we need to configure. I can't burn or debug a project on STM32 IDE. 05mA, but RAM is lost and reboots on wakeup. cpp and ensure the appropriate lines for the. The optional LED1 diode indicates the 220v power is applied to the Hot Air Gun socket. • The embedded programmable voltage detector (PVD) is disabled. ) The STM32-DVM-MTR2K contains no trim pots. // Set static session parameters. Finally,tick " Run and Reset " Options. And the relay would completely disconnect the power line if the hot air gun is not active, even when the hot air gun would being cooled down. Low Power Sleep Mode : CPU is stopped and the active peripherals are limited and working at reduce frequency. On the rising edge, the module is reset. By default, the microcontroller is in Run mode after a system or a power Reset. Do not power this board through USB and an external power supply at the same time. Three pins are needed for the interface (CE, I/O, SCLK), and Vcc2 should be connected to +5V (or +3. Below are the code for system clock config, RTC Init, and the code to read the RTC registers after reset. Minimum amount of time (in milliseconds) OpenOCD should wait after asserting nSRST (active-low system reset) before allowing it to be deasserted. I don't think it will make a difference for the STM32 and Crossworks but certainly will for a Segger JLINK. Testing!Now before adding the coin cell holder, I tested whether. By default, the microcontroller is in Run mode after a system. - IWDG (Independent Watchdog), WWDG (Window Watchdog) IWDG 는 LSI 로부터 clock 을 제공받는 12-bit down counter 타이머로서 HSI/HSE clock 에 문제가 발생하여도 독립적으로 동작할 수 있다. No external reset circuit is required. In order to do so, you need to do the following: Press and hold down the Boot button. 40V and up to a maximum voltage of 5. 8V, then DVDD is generated by internal regulator of. #define BOR_LEVEL OB_BOR_OFF /*!< BOR is disabled at power down, the reset is asserted when the VDD power supply reachs the PDR(Power Down Reset) threshold (1. Operating conditions at power-up / power-down (regulator ON). device/function reset Reset triggered by sending reset command to a device. Thus time is not varied or lost during powered down and sleep modes. Sleep uses very little power, your PC starts up faster, and you’re instantly back to where you left off. STM32 dilengkapi dengan POR (Power On Reset) dan PDR (Power Down Reset), yang akan memastikan saat power on dan power down, STM32 berada di kondisi reset saat tegangan catu daya < 1. 0: Top view WeAct Black Pill V2. Power‐on reset & Power‐down reset, permanently enabled (zero power). Just pull BOOT0 high, reset with the USB connected to a PC and use DFU-Util (on Linux) or ST's DFuSe app for Mac/Windows. If you have more than one GPIO pin available you can speed up the process. Voltage supervisors are often used with processors, voltage regulators and sequencers – in general, where voltage or current sensing is required. Nothing special… Note that we are operating the AD9850 with 3v power supply since the stm32 logic pins are 3v. Calibration is started by setting the CAL bit in the ADC_CR2 register. Therefore, this lag time is very necessary. Understand how the Stack and Heap are organised. After doing that press the RESET button on the board. Reset embedded in the Reset block . In short, connect pin 5V to pin Boot by using a 270Ohm pull-up resistor. Open-Drain or Push-Pull gate on output. The reset button on some of these boards is very hard to press. All DVDs of an STM32 can be turned off or in other words, the entire MCU core can be fully shut down but the battery backup keeps the RTC and the backup domain running. Go to the last bar/option " Utilities ". Power supply supervisor The device has an integrated power-on reset (POR)/power-down reset (PDR) circuitry. After that, navigate to Files—>New Project—>C project, and the new project’s viewpoint will appear, as seen in the figure below. Capable to program all ARM Cortex M core chips. 6 V; Power-on/Power-down reset (POR/PDR) Programmable Brownout reset (BOR) Programmable voltage detector (PVD) Low-power modes:Sleep, Stop, Standby, Shutdown; V BAT supply for RTC and backup registers; Clock management. When you've had enough strings, feel free to press the stop button in the IDE to stop the program from running on the STM32. Reset This is a simplified diagram of the reset circuit inside the STM32, however newer parts may have revised this internal circuit so always make sure to double check your STM32's datasheet. Each GPIO Pin has a complex structure to function as both input and output: Protection Diodes. Based on the documentation, this should automatically switch the RTC power source from VDD to VBAT. The Device Has An Integrated Por/Pdr . The goal of the STM32-base project is to provide a simple and easy to use base project for working with STM32 microcontrollers. To run the code on the STM32 Board, click the resume button in the Debugger perceptive. Stop Mode: In Stop Mode the CPU core is stopped but the RAM and Register are retained. Its function is to monitor the supply voltage. DELL XPS-13 9360 requires hard power-down after sleep. They are ideal for code shadowing to RAM, executing code directly from Dual/Quad SPI (XIP) and storing voice, text and data. Pressing reset helps, but only if it's done 1. 27f66910d8d3 100644--- a/drivers/remoteproc/Kconfig +++ b/drivers/remoteproc. The backup SRAM when the low-power backup regulator is enabled PC13 to PC15 I/Os, plus PI8 I/O (when available) The switch to the V BAT supply is controlled by the power-down reset embedded in the Reset block. It looks very much similar to the Arduino Nano but it packs in quite a punch. The calculator will not turn on until all the steps have been completed. 3V for the micro and other devices. The Winbond W25Q80DV array is organized into 4,096 programmable pages of 256-bytes each. Power Reset A power reset is generated when one of the following occurs: Power-on/power-down reset (POR/PDR reset) When exiting Standby mode A power reset sets all registers to their reset values except the Backup domain These sources act on the NRST pin and it is always kept low during the delay phase. As of this writing, SparkFun is using the DFU bootloader to upload code to the STM32 Thing Plus. Once data ready is set, It will send joint commands to 12 motors and set dataready = 0. Clock, reset and power management: 2. • in Run mode, the regulator supplies full power to the 1. It eases migration from the 16-bit world thanks to its high. To accomplish this you have two options. Per your comments about reset, I decided to get the scope on reset. TCK, RTCK, DBGRQ and DBGACK should have a pull-down of 10k normally; Note that nSRST is the system reset and is normally connected to the RST line on the target processor. One description of this voltage is “False Power”. 6V voltage range, power-on/power down reset (POR/PDR) 4 to 32MHz crystal oscillator, internal 40KHz RC oscillator; 39 GPIO, 5-channel DMA controller, 17 capacitive sensing channels (10 ext + 3 int) channels 12bit ADC, one 12bit DAC channel, two analogue comparators. This part is used to program (flash) the target F401 device and provide the USB Serial interface to the host. Setting different BOR (brown-out reset) levels. 2)power reset ・power-on ・power-down ・スタンバイモード. Then, BOOT0 becomes a logical 1 and boot mode is enabled (after a reset!). Low-level STM32 Peripheral access. Jeffro_Aus February 27, 2016, 6:15am #1. gpio_get returns bits in original position. All devices are offered in space-saving packages. I have a project made it with CubeMX. We will see if that helps the situation. This board allows users to develop and design applications. This sleep mode is similar to the power-down mode, only with one exception i. A timer (sometimes referred to as a counter) is a special piece of hardware inside many microcontrollers. Buzzer is connected to collector side of the npn transistor with a. I have a new programming cable on order. RESET# is active low with internal pull-up resistor. This article contains some simple examples to understand how to deal with push-buttons when you are approaching STM32 and ChibiOS. The STM32 Black Pill is a high-performance, ARM ® Cortex ® -M3 32-bit RISC core operating at a 72 MHz frequency. This means you don’t need any python code to reset the Raspberry Pi, you can use jumper wires or simply a push button to reset the Raspberry Pi. Programming Manual provides the following: Processor Modes, Stacks. The Power, Reset and Clock Control Unit dialog configures the power saving mode, clock dividers, boot configuration and the core, memory and peripheral . 25V measured at the upsteam plug of the device. 1MHz “MSI” (Multi-Speed Internal) oscillator on an STM32L0 chip. Make note of the absolute maximum rating tables available in the STM32’s datasheet, particularly the maximum voltage and current limits of each pin and overall microcontroller. Hi, I'm currently extending the operating time of my standalone Arduino chip, which runs on batteries, by putting it to sleep when not in use (power down sleep mode). Voltage supervisors are often used with processors, voltage regulators and sequencers - in general, where voltage or current sensing is required. 일렉트로닉스/STM32 회로설계에 있어서 가장 기본적인 전원, 클럭, 리셋, 부트모드, Standby mode : regulator 파워다운 상태다. upload the code, it working without a click reset button. The internal power on reset and power down reset ensure the processor only runs with a stable power supply. The host MCU, along with the rest of the peripherals, demands regulated and noise-free power supply. bus reset Reset bus and devices on the bus. Hardware based on chip STM32F103C8T6, firmware based on X893 github open source project. 3 Voltage regulator The voltage regulator is always enabled after reset. Unfortunately the LSI clock is not on the list, that's why it and the RTC stops when V DD is gone. (some state might be left unknown. Task 1 - > User Interface and menu selector. // We safe some data in the RTC backup ram which survives DeepSleep # define DEEP_SLEEP false # if DEEP_SLEEP # undef OTA # endif # endif # define led LED_BUILTIN # define voltage PA0. PA15 ping of stm32 controller can manage the safety relay that connect 220v AC power when hot air gun activated only. Liberal serial debug output (printf) is great for tracking the general flow of your. Connect your calculator to a USB port on your computer. 1 Power on reset (POR) / power down reset (PDR) The device has an integrated POR/PDR circuitry that allows proper operation starting from 2V. One 1uF capacitor placed anywhere on the spots reserved for capacitors on the power trace. But actually in your log, you write 01, 00 to the sensor. As you understood it right STM32 must act as Tunnel / DFU-controller to send Firmware to NRF, but not via PC or nrfutil. LMIC_setSession ( 0x1, DEVADDR, NWKSKEY, APPSKEY); # endif. An NPN transistor is used in the project. While Espruino provides an easy-to use way to access the peripherals on the microcontroller, the hardware itself is amazingly complex and capable, and can do far more than can be exposed to you in JavaScript. Now for info STM32 has Bootloader and updates itself via CAN communication from a Tool. This is so the microcontroller always starts in a known state when first turned on. The STMicroelectronics STM32F030K6 is a Core - ARM 32-bit Cortex-M0 CPU (48 MHz max) Memories - 16 to 64 Kbytes of Flash memory - 4 to 8 Kbytes of SRAM with HW parity checking CRC calculation unit Reset and power management - Voltage range: 2. Reset Sequence in ARM Cortex-M4 - Example execution. For using STM32 development you have to install an external debugger plugin called Embedded Plugin Suite (EPS) Code::Blocks IDE is free but EPS costs about €120 per series, ie if you want STM32F1 and STM32F4 support you have to pay €240. • Reset and power management Digital & I/O supply: VDD = 2. For example, for the bhy reset function, we need to write 0x01 to register 0x9B. Next, I set the RTC in my code and then I disconnect the MCU from power source, and then reconnect it again. The power-on reset function (POR) b. 2) POR = Power On Reset power-on reset; PDR = Power Down Reset power-down reset. Wait for 1 minute, then reconnect the AC adapter or power up using the battery. 20 depend on the memory configuration. The analysis reason :STM32 In addition to power on and power off reset , most STM32 There is also an undervoltage reset , When the supply . I want to use AD7797 with STM32F103C8 for data logging. Search for jobs related to Dm368 spi or hire on the world's largest freelancing marketplace with 18m+ jobs. Here's how to reset the NVRAM: Hold down Option/Alt, Command, P and R. You'll get to know these different hardware variants and their application use cases. 5-2 seconds after the power is applied. After a shut down they are always high. The code is nothing more than a calculation of the DDS tuning word and manipulating the GPIO portD to send the data. 6 V - Power-on/Power down reset (POR/PDR) - Low power modes. The Cortex®-M0+ core has direct access to the GPIO registers through the single-cycle I/O port bus. Now transistor controls the buzzer and transistor is controlled by stm32 microcontroller. One 10K resistor nearest to the reset button and one 100nF capacitor next to the resistor. program and use HAL functions to blink a LED on the NUCLEO-L476RG board. Pull-up and Pull-down resistors on input. The device remains in the Reset mode as long as VDD is below a specified threshold, VPOR/PDR, without the need for an external reset circuit. Basically you can program a 32KHz wake-up in this mode. The shutdown mode is reached when you power off your system (even if you have VBAT connected), which is your case. mai 03, 2020 10:29 pm You need to set RTC source to LSE if you want it to work in shutdown mode or without power (just with RTC battery). STM32F0/F3/F7/L0/L4 시리즈는 windowed 모드로 동작할 수 있다. 68V); BOR(Brownout Reset) : threshold . When this pin goes low, hard power-down is enabled. If it's mismatched there can be temperature dependency, perhaps the explanation for your problem. Use this device to send program code to the 32-bit STM32 ARM Cortex or 8-bit STM8 microcontrollers. TIM_ITConfig(TIM2, TIM_IT_Update, ENABLE); This will enable the ‘update’ interrupt for the timer. By using the above code, the Arduino will go into a sleep of eight seconds and wake up automatically. 2 V domain (core, memories and digital peripherals) • in Stop mode, the regulator supplies low power to the 1. The internal 8-MHz oscillator and ULP co-processor are disabled and the RTC recovery memory is powered down. I have a DELL XPS-13 9360 which won't resume from sleep mode - if it sleeps, I have to press and hold the power button (15 - 30 seconds, something like that) to hard restart the laptop in order to get it to boot. I am using a 24Vdc SMPS to provide power to the board. Unless you have a variable power supply, you’ll need an on-board regulator to provide the appropriate supply voltage. down reset) or by setting the CSBF bit in the Power control register (PWR_CR) 0: Device has not been in Standby mode. if the timer/counter is enabled, it will remain in running state even at the time of sleep. Command: adapter srst delay milliseconds. The upper half of the given table is the programmable monitoring. Stop Mode Sleep Mode Standby Mode Stop mode features In stop mode, the real-time clock is powered by LSI (low speed internal) clock source. With the embedded Arduino MCU and RTC, the HAT features auto power management function which allows the Pi to work more power-efficient and more safely. Power Pin of STM32 Nucleo F401RE. In my opinion, it may be very rude . This means that a Power-On Reset // (POR), Power-Down Reset (PDR), . There are multiple versions of this board with different connectors. Sleep mode When Cortex-M3 encounters WFE (Waiting for Interrupt) or WFI (Wait for Event) instruction, it will stop the internal clock and carry out program execution. I'm working with Windows 10 and STM Ide version 1. Therefore, I guess the procedure may be like this: after the user presses the power button, the circuit should send the highest priority interrupt to. VTREGs (Virtual Target Registers) which support I/O with the peripheral. This header is usually a male dupont header, but female headers are also used. In order to upload code to the STM32 Thing Plus, you'll need these two buttons to put the board into Boot mode. Check the nucleo manual for details. STM32 는 2가지 종류의 watchdog 타이머를 제공. 72V); PDR - Power-Down Reset : Vpdr 이하이면 리셋 (1. Under USB Support, select CDC (generic "Serial" supersede U (S)ART) Under Upload method, select SMT32CubeProgrammer (DFU) Use the onboard BOOT0 and NRST button to put the board into bootloader mode:. The STM32 Flash loader demonstrator (FLASHER-STM32) is a free software PC utility from STMicroelectronics, which runs on PC and communicates through the RS232 with the STM32 system memory bootloader. When the power supply voltage (VDD) drops to the selected V BOR Below the threshold, the chip will reset. To reset a keyboard, try the instructions given below to change the keyboard language. Release the reset button and then release the identify button a second after Your PC should make an audible sound when this process is successful as windows is detecting a new USB device. Scroll to continue with content. I always receive 0x00 as output from. By grouping the pins together it is also possible to plug in a 40-pin IDC ribbon cable and the multiple GND pins preserve signal integrity. 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