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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1answer
57 views
Connecting the RESET pin of AT8051
How should I connect the RESET pin in a microcontroller (AT8051), and why in that particular way?
3
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2answers
78 views
Board occasionally resetting when dropped or knocked
I have a board that consists of
Arduino pro mini (ATMega328P, ceramic resonator, tactile reset button)
SD card
I2C sensors
LTC3525 boost converter (IC, inductor, caps)
Very occasionally, if the ...
0
votes
2answers
178 views
Given a gated SR latch, How do I make it a set dominant gated SR latch?
Another weirdly worded question in my digital logic book. It doesn't specifically define set-dominant or reset-dominant - nor does it show how to use these in practice with drawing circuit diagrams. ...
-1
votes
1answer
37 views
Is RST valid while programming with ISP?
First time designing a PCB board whith a MPC82G516AP (8051),I'm using an external Watchdog Timer chip。So is the watchdog reset valid while programming with ISP?
1
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1answer
59 views
Resetting a 74xx164 on power-up
I while a ago I saw a circuit in a datasheet that automatically cleared a 74xx164 shift register on power-up. I don't exactly remember which logic series it was (might have been LS or HC), and the ...
3
votes
2answers
111 views
Reset pin on ATtiny84/85/2313 clarification
I have two questions that I was hoping someone could clarify with a quick True/False. When using the ATtiny85/85/2313 the reset pin is connected to a 10k resistor which is connected to VCC.
When ...
1
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2answers
114 views
Pullup or direct drive when handling active low inputs/resets?
Active-low reset inputs seem to be a holdover from TTL logic where the falling edge was faster than the rising edge, so the falling edge was decided as more important to increase the maximum possible ...
3
votes
3answers
244 views
Generate a reset signal from a falling edge trigger
I'm working on a microcontroller design where the mcu is placed in hibernation mode, and can only be awoken by a pulse(high-low-high) signal on the reset pin. (active low)
As a wake-up source i'm ...
1
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2answers
90 views
Electronic Reset SW
Normally, there is a mechanic button at the end of the RESET SW pins on the mainboard. Now, I like to create a way to electronically trigger the reset function of my mainboard from another computer. ...
3
votes
1answer
90 views
PICKIT 3 resets PIC16 three times upon reprogramming
I am using the PICKIT 3 with MPLAB X with the default setings. When I press F6 to build and run my code, I notice that the PIC16 resets three times:
twice with ...
3
votes
3answers
132 views
Effective use of output signal of a watchdog timer
Subsequent to my previous question regarding watchdog timers, I am interested in deciding the RESULT of such a watchdog:
Assume I add a generic external watchdog timer to my circuit. If not toggled ...
7
votes
2answers
944 views
What values of resistor and capacitor to use for AVR reset pin isolation?
Background...
I'm a newbie to AVR applications. I recently built two ATTINY13-based circuits (glorified LED blinkers) which worked correctly (independently) on the breadboard. When I combined them on ...
3
votes
1answer
305 views
Using AVR reset pin as ADC
I am using an ATTINY13 for a toy application. It simply blinks LEDs in specific patterns. I decided to add a "speed control" using a potentiometer but the only pin I had left is the reset pin.
I've ...
2
votes
1answer
618 views
STM32 NVIC interrupts after a reset / power-on
I have a few active-low signals that I want to interrupt on. During normal operation, the interrupts work just fine. However, on reset / power-on only rising edge is detected.
In other words, on ...
5
votes
3answers
197 views
Using reset controllers with modern microcontrollers
Are reset controllers necessary for modern microcontrollers, such as the LPC2138 or 9S12XD256? Most ARM processors I have seen have their own brown-out detectors and reset properly, and I don't see ...
0
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1answer
220 views
Is RESET* on the XMEGA disabled when using the PDI interface?
When PDI CLK is connected on the XMEGA (also the RESET*) pin, can this pin still be used to trigger a reset on the chip? If so, how does the chip tell the difference between PDI being used as a clock ...
0
votes
2answers
403 views
Resetting XBee with an Arduino
I would like to be able to reset an XBee with an Arduino by connecting the reset pin on the XBee to a General I/O pin on the Arduino. I'm wondering if any additional components (transistors, resistors ...
3
votes
3answers
710 views
Atmega32 factory reset board
I want to know is there any reset board available ( I mean schematic, link, tutorial or anything else ) out there for Atmega32 microcontoller ( I heard about high voltage reset board, I found some ...
3
votes
2answers
229 views
Electrical reset to a SIM card
I have a SIM card reader connected to an ARM, and I'm trying to get the SIM to send an Answer To Reset (ATR) and to get the reader to capture it.
As I understand, an ATR is sent after an "electrical ...
2
votes
2answers
2k views
STM32: Performing a software reset
I am trying to perform a software reset of my STM32F2. (Reference manual available here.) The relevant page of the reference manual (page 80) gives little information. Basically, the ...
4
votes
3answers
620 views
Do AVR registers and ports need to be initialized to zero?
During the initialization routine of my code I use to do such things as:
clr r0 ; will always stay zero
and:
...
0
votes
1answer
349 views
Hard resetting an STM32
My STM32 is behaving weirdly, to say the least. What is the best way to "hard reset" an STM32? I've tried pressing the "reset" button, and unplugging/replugging everything, but it seems like the ...
2
votes
4answers
392 views
What is the common pin configuration upon microcontroller reset?
I have looked through two datasheets and user manuals now for two different microcontrollers (LPC2387 and STM32F4xx), and I haven't found (probably missed) anywhere where the initial state of the GPIO ...
0
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1answer
659 views
Xbee Factory -Hardware reset without serial communication
I'm using "XBee 802.15.4 Module"
After successful connection with X-cut & made a "+++" it responded "Ok"
Then is stopped working ....
I tried to reconnect to it again & failed .. it no ...
2
votes
2answers
103 views
Device is reset when switching power sources
I use a home weather station. It is powered by two AA batteries (2 x 1.5 = 3.0 V nominal). The problem is that it eats more than 1 mA and that is quite a lot of power and I must buy a new pair of AA ...
4
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4answers
482 views
How does a latch determine its initial state?
How does a latch get its initial state? I'm guessing that it depends on race conditions and which ever condition comes first then that is the state that the latch starts off with.
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0answers
521 views
Atmega328 reset pin not working after re-burning Arduino boot loader?
For a bit of background you might want to read
atmega328 with optiboot not compatible with Arduino?
But I will summarize anyway. I have some Atmega328 chips that shipped with the optiboot ...
2
votes
1answer
797 views
Can an ATTiny with RSTDISBL programmed be reprogrammed over ISP?
The ATTiny85 datasheet, on page 152, seems pretty clear on this:
After this fuse has been programmed device can be programmed via
high-voltage serial mode, only.
But elsewhere, on page 28, it ...
7
votes
4answers
1k views
Reset: synchronous vs asynchronous
I've been working with fpgas for years, and always used synchronous resets for every parts (that need it) of my circuits. It helps the circuit to be globally reset at a given clock cycle.
However, I ...
2
votes
1answer
285 views
MSP430 Illegal Instruction
A few questions here along the same lines, I'm looking at the datasheet for the MSP430x2xx family (I'm using the MSP430F235 FWIW). It says there in section 2.2.4 that "illegal instruction fetch" is an ...
4
votes
2answers
71 views
Controller Resets after Enabling Cache
I am using a MCF5253 controller which is based on Coldfire Architecture.
It has 8KB of Instruction Cache.
Everything was working fine till I enabled it's Instruction Cache.
Now what's happening is ...
1
vote
5answers
273 views
Does reset do the same thing as shutting off the power to this device and turning it back on?
I am trying to control a serial dataflash memory through an mbed. It is an AT45DB021B and the datasheet is here. It has a reset pin that I have wired to the mbed so that a software reset can be done. ...
3
votes
1answer
2k views
How does the Arduino Deumilanove Auto-Reset Function work?
I'd like to hear some explanations as to how the Arduino Duemilanove resets the ATMega328P over USB through the FTDI FT232R transceiver.
I know it involves the IDE playing some games with the DTR ...
7
votes
3answers
409 views
(Updated) Strange reset behavior with ARM9 processor
I'm working on debugging a boot problem with an Atmel AT91SAM9G20 board. Everything goes great for the first 700 ms or so. It seems that about 700 ms after reset, the processor freezes. What's curious ...
4
votes
3answers
691 views
Is it possible to reset NXP LPC2100 microcontroller from code
I'm curious? A watchdog timer could do this, but I would like to do it manually.
8
votes
3answers
1k views
Arduino reset with FTDI breakout question
How do you get the SparkFun FTDI Basic Breakout board to auto reset?
http://www.sparkfun.com/commerce/product_info.php?products_id=9115
I still have to hit the rest button for any Arduino clones when ...
3
votes
2answers
908 views
Arduino chip wipe on reset
Does the Arduino chip get wiped of any (uploaded) code when you press the reset button?
and
Can you retrieve the code that is currently on the chip?
