Unanswered Questions
29,164 questions with no upvoted or accepted answers
24
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answers
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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 ...
- 116
9
votes
0
answers
500
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How to understand a complex diode-resistor function generator circuit?
I'm reverse-engineering a CRT anti-pincushion circuit and it uses a complex diode-resistor circuit to approximate the function \$X-k×X×Y^2\$, where \$X\$ and \$Y\$ are the deflection voltages. My ...
8
votes
1
answer
304
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Clock generator output off by a factor of sqrt(2)?
I'm using the Si5351A-B-GM clock generator with the NX5032GA-25.000M-LN-CD-1 (25 MHz, 8pF) crystal. The fragment of the schematic is shown below (the rest of the schematic omitted for clarity):
...
CommunityBot
- 1
8
votes
0
answers
261
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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 ...
- 4,663
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
votes
0
answers
160
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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
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0
answers
400
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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 ...
- 1,067
7
votes
1
answer
916
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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
- 1
7
votes
2
answers
272
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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
votes
0
answers
195
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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 ...
- 711
7
votes
1
answer
5k
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STM32F0xx UID decoding
In my project, I need to make readable 96-bit UID. In STM32F0xx reference manual RM0091 section 33.1 Unique device ID register, it is described how the number is encoded:
...
CommunityBot
- 1
6
votes
0
answers
161
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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 ...
- 14.7k
6
votes
0
answers
206
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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♦
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6
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0
answers
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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 ...
- 28.8k
6
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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