Questions tagged [reset]

The reset line on a computer or other digital circuit places the circuit in a well defined initial state. Most microcontrollers have a built-in power-up reset to start the CPU executing code and may also have external resets and watchdog timers to help recover from unexpected events.

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54 views

Reset and trigger 555 timer with one push button

I want to turn on a LED with a single push button. When the button is pressed, the LED has to be turned on for an X amount of time. But what I also want, is to turn of the LED with the same push ...
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66 views

CD4043 latch breadboard VS PCB

I am working on a circuit that contains CD4043 R/S latch. The design on the breadboard works and everything is great, as soon as the PCB was manufactured and components were soldered, an issue with ...
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72 views

Discharge capacitor faster during reset

The part under consideration is UDA1334BTS - the DAC I use in my design. Here's the typical connection diagram: If the circuit is being powered off, and then quickly on, the Vref voltage does not get ...
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66 views

Why is does my board stop responding periodically when the motor is hooked up?

I have built a stand alone Arduino type board. It will run all day long as long as no actuator is hooked to the relays, the voltage on a voltmeter shows when the motor changes direction properly. ...
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32 views

STM32F103CBT7 dev_target_held_under_reset problem

I have a PCB with the STM32F103CBT7 microprocessor. I used the ST-Link V2 with the STM32CubeProgrammer to programm it which I think worked the first time as it connected and and ended programming ...
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57 views

Impact of a reset pin higher than VDD

The datasheet of a chip describes the circuitry of the reset pin the following way: The reset pin is described as a pull-down. The chip is powered at 1.8V - the recommended/acceptable values are ...
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50 views

Reset circuit of CP2102N and Atmega328P

I am working on a project where I want to programm the atmega via usb serial connection, just like an arduino. In order to do that, I have wired up both chips as the documentation suggests. The reset ...
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21 views

Restarting ESP8266 NodeMCU in DeepSleep with a signal from HM10 BLE

I'm building a simple project in which I put the ESP8266 NodeMCU board in DeepSleep mode, so I can save some battery since it's powered with 4 AA batteries. What's the problem? I don't want my ESP to ...
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94 views

Why does the voltage value on the RESET pin of my microprocessor not go high?

I am facing an issue that I do not understand. I am using a STM32F030K6T6 microcontroller with a capacitor X7R 0603 100nF 10% 50V connected to the ground, whose the value corresponds to the ...
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34 views

Raspberry Pi: How to connect global_en with gnd on a 5v signal?

On a Raspberry Pi 4, you can perform a hard reset by pulling the global_en pin to low. I want to control this reset by using an external 5v signal. When the signal is high, the reset is performed. I ...
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31 views

Limiting high input voltage on a CMOS input

I have a CMOS IC that has a low level RESET input. I would like to connect it to MCLR pin of my Microchip CPU but this is problematic because programmer/debugger (Microchip ICD) can put there a level, ...
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STM32F103 random reboots

we have made a 2 layer board for a STM32f103, and apparently it works fine but we get a random resets now and then. When that occurs there is a 1 in the Bit 27 PORRSTF: POR/PDR reset flag and Bit 26 ...
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Should I use an asynchronous or synchronous reset?

I am programming a Microsemi M2Gl005 FPGA and wondering which type of reset I should use. I currently have an asynchronous reset implemented, but I wanted to make sure that the part didn't prefer a ...
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106 views

Oscillating value of reset pin

I have a custom board STM32WB55CGU6 with a reset pin connected to a pull-up resistor and a capacitor as shown in the schematic and PCB layout below (connected to the reset pin 7): Using an ...
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104 views

Search for “pinhole” SMT switch (like “reset” switch operated with paperclip)

I search for a small switch, momentary on, SMT mounting type, I can put on my STM32 board for entering DFU. I search for a small switch with only a small hole to put a pin or a paperclip. I thing I ...
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Reason for x86 reset vector being at 0xFFFFFFF0 instead of 0xFFFFFFFF

The top answer to this question on Super User gave an explanation that was satisfactory to me at first as to why the reset vector is not at address 0 (afterwards , I realized that it doesn't why the ...
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48 views

Does not Reset Handler move along with NVIC vector table?

My board: STM32F407G-DISC1 (based on STM32F407VGT6 microcontroller) See reference manual. (pages around 371 are related) My understandings Each interrupt service routine is located in a memory address,...
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37 views

Brown-out detection with an external clock ATmega1280

I'm using ATmega1280 with an external clock and I have some questions about the "safe operating area" for preventing EEPROM corruption with BOD. The external clock is: Crystals 14.7456MHz ...
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30 views

Microcontroller Vol Maximum Voltage compatibility

I am having this microcontroller - S32K142 64 pins - 5V Core voltage I have the below RESET signal connection which is provided by the MCU to the below transistor (which provides RESET to another ...
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49 views

Continuous Reset generated by LDO to Microcontroller

I have the below schematic Datasheet of the LDO - L4995 -SSO24 package LDO Specification : Input Voltage : 12-16V Output Voltage : 5V Load Current : 100mA Issue : My LDO is generating RESET ...
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1answer
114 views

Building a T flip-flop with enable and reset using only a JK flip-flop that has no enable or reset, and use some necessary logic gates

I am confused about whether if I should use don't cares to fill in the J and K on the state table, or just use keep and change. If I use don't cares I will not get any Q inputs (as seen on the K-maps),...
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44 views

USB to ethernet chips like LAN7850 require GPIO to RESET pin?

I am designing a PCB which uses LAN7850 chip This is the first time I'm using such a chip and I'm very newbie to PCB designing. Please advise if this Chip requires a GPIO pin from the ...
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51 views

Resetting 555 via Transistor - RESET PIN LOW TOLERANCE

I have a circuit with a NE555DR timer that generates a pulse. The reset is held low and lifted when a voltage of 5 - 24V is applied to P0-3. A PNP transistor MMBT5401 that pulls pin 4 to ground when ...
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99 views

Basys 3 FPGA sequential circuit reset remotely?

Since the COVID-19 pandemic, I'm teaching Verilog lab online. I let each student remotely connect to a computer having Xilinx Vivado installed, a Basys 3 board connected and powered on, and a camera ...
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29 views

One-way JK flip-flop using 74xx109

I want to design a flip flop circuit that effectively has one input and one output, as well as a reset trigger, along with clock and power, using a 74ACT109 JK flip flop. Basically, the output and ...
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What is the use of NRST pin in STM32F401RCT6?

What is the use of the NRST pin in STM32F401RTC microcontroller. I am using the SWD interface to program and debug flash memory of the controller. I am finding NRST pins in both microcontroller as ...
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78 views

Hard Reset variable change in MCU

I have an activation system with a unique password per activation operation. If the system goes down or is not working correctly and I need to reset it to a operational state I could design a hard ...
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61 views

STM32F4 read protection cause MCU hang

I've faced a problem using read protection on STM32F412. When read protection enabled from Level 0 to Level 1 MCU hangs and does not recover after the reset with reset the pin, only after a power ...
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54 views

Handling of reset with multi bit clock domain crossing

I have an SoC design with two clock domains, each with it's own asynchronous reset (which roughly means asynchronous assertion of reset and synchronous de-assertion). I am trying to pass a 64 bit ...
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1answer
101 views

Verilog finite state machine won't reset (asynchronous) current state to initial state (shows xx)

I have mostly worked on VHDL and I have recently started learning Verilog. I wrote a Moore Finite State Machine (FSM). The FSM is not resetting properly as current state upon reset doesn't go into ...
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59 views

MOSFET gate spikes when load is disconnected

I have a system that has two fan banks driven by MOSFETs. The fans are mounted on two sides of the enclosure on ~2 ft cables. After one second from system turn-on the microcontroller turns these FETs ...
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1answer
66 views

Desoldering CPU from PCB or holding it in reset

I am currently working with a NAND flash that I want to dump. The goal is to take a look at the data that is stored in the filesystem. To do so I soldered 8 wires to the NAND flash to access it while ...
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1answer
190 views

Remote reset circuit does not work

I have a custom board based on an Atmega168A which I would like to reset when the power switch to the on-board LEDs is switched off. Resetting the uC by shorting RST and GND works on the ICSP ...
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2answers
124 views

Microcontroller working voltage + brownout circuit

I'm working with LPC1769, but this applies to any MCU. The datasheet states that the power supply range is from 2.4V to 3.6V. The included brownout detection circuit triggers a warning interrupt ...
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1answer
70 views

Uninterruptible Power Supply - Reset the load when power is restored

My system is powered by a redundant supply (UPS). When the input power supply is removed, the system detects this event and it performs a safe shutdown (actually it is a microcontroller that enters a ...
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59 views

ICSP + FTDI for ATMega328P

I want to have this "debug" header with 10 pins (I could probably get away with 9) and I am wondering if the DTR pin is ok to be filtered by a capacitor for ICSP. This is how I am sourcing these pins:...
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26 views

AT91SAM7S512 Oscillator, GPIO, & Reset questions

I just need some clarification of my circuit Oscillator: So for my circuit I want to be able to program it via USB, the datasheet gets a bit confusing to me tho. If I read the datasheet correctly I ...
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1answer
59 views

Triggering CD4026 Reset w/ a CD4017

I am trying to get a CD4026 IC to reset at 6 for a digital clock project. I have some 3-input AND gate IC's but there doesn't seem to any unique conditions that would work. I do have some CD4017 and ...
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84 views

STM32F072C8T7 needs hardware reset upon power on to work!

When the device is connected to the ST_LINK, after firmware upload, it works perfectly fine. When I remove the ST_Link and then turn OFF and ON my device, it does not work, unless I initiate a hard ...
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“recommended that CLK begin toggling within 150 ms … to ensure long-term reliability of the device” — why?

In Intel's Pentium Processor Family Developer Manual, regarding the CPU clock, it says that "it is recommended that CLK begin toggling within 150 ms after VCC reaches its proper operating level. This ...
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Board is getting reset when I lower the temperature in Thermal Chamber

I have a board which I put in the thermal chamber. I increase the temperature inside the thermal chamber to 85degC. Soak it for 2 hours and note some readings. Then, when I change the temperature to ...
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47 views

Decoupling on Power-on-reset-IC

Is it a good idea to place the usual 100nF decoupling capacitor on a power-on-reset chip? Mightn't that influence its behavior on brown-out or power dips? What is the best approach here? The power-...
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2answers
96 views

Can the watchdog on an STM32F373 trigger a reset while the RESET pin is held high?

The reset pin on an STM32 chip is being pulled high by a Raspberry Pi Zero W in the field via GPIO pin BCM 17. Will the watchdog on the STM32 be capable of triggering a reset while the pin is being ...
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400 views

Program ESP32-CAM via FTDI without manual reset?

When programming the ESP32-CAM with an FTDI, I proceed as follows: Connect GPIO0 to GND. Reset the ESP32-CAM. (by cutting power)...
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103 views

What is the proper way to reset attiny85?

I have 3 attiny85 on my pcb. And I want to have software controlled reset for them. A separate STM32F0 microcontroller is responsible for the reset. I have two states from the STM32F0 to pull up and ...
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1answer
254 views

Lattice MachXO2 reset

After reading about GSR/PUR facilities in Lattice FPGAs, I'm still a bit puzzled about how to actually get the proper GSR/PUR-based reset functionality on an actual physical FPGA chip. In the How to ...
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3answers
160 views

Flip flop asynchronous reset timing

Let's say you unassert an asynchronous reset signal to a flip flop after you need to to meet setup timing but before the positive edge of the clock. You're in trouble right? Now let's say you've got ...
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2answers
217 views

What is automatic global reset on FPGA?

I recently asked a question that ended up involving answers about an automatic global reset capability that FPGAs have, and though the question got solved, I'm still quite unclear about this, and ...
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2answers
128 views

Why are registers being turned on to 1 before reset/on button is hit on FPGA?

I am writing a really simple program on Verilog for my FPGA to have an LED blink once a button is pushed. Here is the code I have written: ...
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117 views

How should a watchdog timer be used? [closed]

I've seen and written programs in which the internal watchdog just resets in a super loop and trigers only when something goes wrong and forces the whole system to crash. I've also seen it can be ...

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