Unanswered Questions
29,191 questions with no upvoted or accepted answers
25
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Switch from JTAG to SWD with bitbang sequence on STM32F103VB
I am trying to switch from JTAG to SWD without any external devices. Why? Because I would like to use the SWO pin to send a stream of logging information to
another device.
To accomplish this ...
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8
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0
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291
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Estimate base-spreading resistance from Gummel-Poon model
I'm attempting to calculate the base-spreading resistance of BJTs from manufacturer-provided SPICE models, which use the Gummel-Poon model. This Agilent publication (Internet Archive link here, if ...
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x86 Motherboard Bring Up - Intel Tiger Lake UP3 CPU
For those who has experience with Intel x86 motherboard design and bring up.
I'm in the middle of motherboard bring-up that has Intel Tiger Lake UP3 CPU.
Seems like I had a good run so far at power-up ...
- 1,077
8
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0
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Is JTAG faster than SWD for debugging on an STM32F with STLINK-V3SET programmer?
There is a new STLINK-V3SET programmer that someone dropped off on my desk today. It supports USB 2.0. My thinking is that if SWD is the bandwidth limiter in the signal chain then a new programmer isn'...
7
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169
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Extremely long net in Xilinx synthesized design labeled "async_path". What's it for?
I used Vivado to synthesize a small design for the Xilinx xc7k-160t-1. The design includes a fifo instantiated with Vivado's XPM macros which crosses clock domains from 100.8MHz to 200MHz.
When I ...
- 1,439
7
votes
1
answer
941
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Modeling scalar control of PMSM
I have met with a scalar control algorithm for a permanent magnet synchronous motor. I haven´t heard about it before so I decided to develop a dynamic model to further analyze this control algorithm. ...
CommunityBot
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7
votes
2
answers
291
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Phase shift near saturation mitigation in input stage amplifier -- How does this work, why does this work?
I'm trying to understand how this circuit works on the input stage to the 4192A Impedance Analyzer.
Apologies for the quality... this is the best scan I could find. The design is furnished with the ...
CommunityBot
- 1
7
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0
answers
204
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Frequency locking for averaging resampling
Background
I've done a long one-shot measurement of a periodic signal by an oscilloscope. Thus, I've captured around 250 periods of a signal. The signal itself is a pseudo-random binary sequence at ...
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7
votes
1
answer
1k
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IIP2 Second Order Intercept Rule of Thumb
I'm faced with the problem of explaining the harmonic production in a system where the second order intercept points of the cascaded components are unknown. As a way to bolster my explanation, I would ...
CommunityBot
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6
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0
answers
178
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Vivante video memory size?
I'm using an NXP i.MX 8MP, with Vivante GC7000UL and GC520L GPUs. Using the Etnaviv open source drivers.
For the life of me, I can't figure out how much video memory is made available to the GPUs, nor ...
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6
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0
answers
227
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Identify kind of cable with markings such as "WE-B 2 PAIR" on the jacket
While cleaning out our back yard shed, I came across a coil of cable of a kind that I have never seen before (image below). It was left here by the previous home owner, who worked in some kind of ...
Null♦
- 7,633
6
votes
0
answers
8k
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How important really is the impedance of an USB 2.0 signal line?
The USB 2.0 specs requires a differential impedance of 90 Ohms and a common mode impedance of 30 Ohms (with some tolerance). This, by definition, gives a target of an odd mode impedance of 45 Ohms and ...
- 1
6
votes
0
answers
2k
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So can we just draw 500 mA from any USB port without enumeration now?
The USB Type-C Spec R2.0 defines the USB Type-C Current feature, in which the power Sink observes the voltage on the CC pin to determine how much current is available from the Source, which falls into ...
- 28.9k
6
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0
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815
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Understanding EGSM-900 (LTE 8 band) electromagnetic spectrum
I am trying to fully understand the physical layer of the GSM standard. For doing that I am looking at the E-GSM-900 band (mostly used in Europe). In my country these frequencies has been assigned to ...
- 185
6
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0
answers
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How to protect single cell Ni-MH battery (overcurrent, undervoltage, overtemperature, etc.) during discharge?
Story
I am designing a boost converter for a battery powered board. I am planning to use single Ni-MH battery. The needed output voltage is 3V3. The device will be in deep sleep mode (drawing few ...
CommunityBot
- 1