<div class="entry-content">
    <div class="jetpack-video-wrapper"><span class="embed-youtube" style="text-align:center; display: block;"><iframe src="https://www.youtube.com/embed/Lqc1jmbSxnE" class="youtube-player" width="740" height="416.418" frameborder="0" allowfullscreen></iframe></span>
    </div>
    <div class="blog-content">
Why is the thickness of PCB layers important? Explained.
    </div>
    
    <div class="blog-content-links">
        <div>
            Links:
        </div>
        <ul class="links-list">
            <li class="links-list-item"><a href="https://fedevel.com/courses">FEDEVEL Online courses</a></li>
        </ul>
    </div>  
</div>

How to choose PCB?

<div class="entry-content">
    <div class="jetpack-video-wrapper"><span class="embed-youtube" style="text-align:center; display: block;"><iframe src="https://www.youtube.com/embed/OG2Ci_xr0pM" class="youtube-player" width="740" height="416.418" frameborder="0" allowfullscreen></iframe></span>
    </div>
    <div class="blog-content">
If you would like to watch a full step-by-step tutorial about how to design your own custom keyboard, let me know in comments. Thx for watching.
    </div>


    <div class="blog-content-chapters">
        <div>
            Chapters:
        </div>
        <ul class="chapters-list">
            <li class="chapters-list-item"><span class="chapters-time">00:00</span><span class="chapters-text">Overview</span></li>
            <li class="chapters-list-item"><span class="chapters-time">00:20</span><span class="chapters-text">Keyboard parts</span></li>
            <li class="chapters-list-item"><span class="chapters-time">00:54</span><span class="chapters-text">Keyboard PCB design</span></li>
            <li class="chapters-list-item"><span class="chapters-time">02:35</span><span class="chapters-text">Small version</span></li>
            <li class="chapters-list-item"><span class="chapters-time">03:53</span><span class="chapters-text">Keyboard case</span></li>
            <li class="chapters-list-item"><span class="chapters-time">05:11</span><span class="chapters-text">Switches and encoders</span></li>
            <li class="chapters-list-item"><span class="chapters-time">06:10</span><span class="chapters-text">Keycaps</span></li>
            <li class="chapters-list-item"><span class="chapters-time">06:56</span><span class="chapters-text">Firmware QMK</span></li>
            <li class="chapters-list-item"><span class="chapters-time">07:52</span><span class="chapters-text">VIA app to set shortcuts</span></li>
            <li class="chapters-list-item"><span class="chapters-time">08:28</span><span class="chapters-text">Finished keyboard</span></li>
    </div>
    
    <div class="blog-content-links">
        <div>
            Links:
        </div>
        <ul class="links-list">
            <li class="links-list-item"><a href="https://fedevel.com/courses">FEDEVEL Online courses</a></li>
        </ul>
    </div>  
</div>

I Built This Custom Keyboard from Scratch

<div class="entry-content">
    <div class="jetpack-video-wrapper"><span class="embed-youtube" style="text-align:center; display: block;"><iframe src="https://www.youtube.com/embed/m3Ny3j5nH0U" class="youtube-player" width="740" height="416.418" frameborder="0" allowfullscreen></iframe></span>
    </div>
    <div class="blog-content">
Close look at BGA soldering, chip soldering, hand soldering and more
    </div>

    <div class="blog-content-chapters">
        <div>
            Chapters:
        </div>
        <ul class="chapters-list">
            <li class="chapters-list-item"><span class="chapters-time">00:00</span><span class="chapters-text">What is this video about</span></li>
            <li class="chapters-list-item"><span class="chapters-time">00:09</span><span class="chapters-text">Soldering BGA</span></li>
            <li class="chapters-list-item"><span class="chapters-time">01:18</span><span class="chapters-text">Soldering TSSOP</span></li>
            <li class="chapters-list-item"><span class="chapters-time">03:05</span><span class="chapters-text">Soldering QFN</span></li>
            <li class="chapters-list-item"><span class="chapters-time">06:02</span><span class="chapters-text">Hand soldering</span></li>
            <li class="chapters-list-item"><span class="chapters-time">08:35</span><span class="chapters-text">Multilayer PCB under a microscope</span></li>
    </div>

    
    <div class="blog-content-links">
        <div>
            Links:
        </div>
        <ul class="links-list">
            <li class="links-list-item"><a href="https://www.keyence.eu/yt-kib-vhx-0924">Microscope Keyence VHX-7000N</a></li>
            <li class="links-list-item"><a href="https://fedevel.com/courses">FEDEVEL Online courses</a></li>
        </ul>
    </div>  
</div>

Have you ever seen soldering THIS close?

<div class="entry-content">
    <div class="blog-content">
        DDR3 mirroring is a feature of memory controller.<br><br>

        See the following text from <a href="http://www.jedec.org/sites/default/files/docs/4_20_19R20.pdf">DDR3 SDRAM Unbuffered DIMM Design Specification</a> (JEDEC website – Registration is required, page 17).<br><br>

        <i>Following pins are being mirrored: A3<->A4, A5<->A6, A7<->A8, BA0<->BA1.<br><br>

        “Since the cross-wired pins have no secondary functions, there is no problem in normal operation. Any data written is read the same way. There are limitations however. When writing to the internal registers with a “load mode” operation, the specific address is required. This requires the controller to know if the rank is mirrored or not. This requires a few rules. Mirroring is done on 2 rank modules and can only be done on the second rank. There is not a requirement that the second rank be mirrored. There is a bit assignment in the SPD that indicates whether the module has been designed with the mirrored feature or not. See the DDR3 UDIMM SPD specification for these details. The controller must read the SPD and have the capability of de-mirroring the address when accessing the second rank.”</i>
    </div>

    <div class="blog-content-img-wrapper">
        <img src="https://assets.fedevel.com/blog/2019/10/8ea2f-ddr3_mirroring_pcb_layout.jpg" alt="DDR3_mirroring_PCB_layout" />
    </div>

    <div class="blog-content-text">
        To confirm this, have a look on the following pictures from <a href="http://www.jedec.org/sites/default/files/docs/design/DDR3/PC3_12800_UDIMM_V07_RC_B0_20070529.zip">PC3-12800 UDIMM</a> layout where I have selected A8 signal:
    </div>
    <div class="blog-content-img-wrapper">
        <img src="https://assets.fedevel.com/blog/2019/10/b9f76-ddr3_mirroring_top_and_bottom_layout.jpg" alt="DDR3_mirroring_top_and_bottom_layout" />
    </div>
    
    <div class="blog-content-text">
        <i>Details of A8 Top and Bottom Layer:</i>
    </div>
    <div class="blog-content-img-wrapper">
        <img src="https://assets.fedevel.com/blog/2019/10/b37e2-ddr3_mirroring_top_layout1.jpg" alt="DDR3_mirroring_top_layout" />
    </div>
    <div class="blog-content-img-wrapper">
        <img src="https://assets.fedevel.com/blog/2019/10/47294-ddr3_mirroring_bottom_layout.jpg" alt="DDR3_mirroring_bottom_layout" />
    </div>
    
    <div class="blog-content-text">
        <i>Screenshot from schematic for D1 and D9:</i>
    </div>
    <div class="blog-content-img-wrapper">
        <img src="https://assets.fedevel.com/blog/2019/10/9bb0b-ddr3_mirroring_schematic.jpg" alt="DDR3_mirroring_schematic" />
    </div>


    <div class="blog-content-text">
        Components D1 and D9 are listed in the BOM with same part number.
    </div>

   
    <div class="blog-content-links">
        <div>
            Links:
        </div>
        <ul class="links-list">
            <li class="links-list-item"><a href="http://www.jedec.org/sites/default/files/docs/4_20_19R20.pdf">DDR3 SDRAM Unbuffered DIMM Design Specification</a></li>
            <li class="links-list-item"><a href="http://www.jedec.org/sites/default/files/docs/design/DDR3/PC3_12800_UDIMM_V07_RC_B0_20070529.zip">PC3-12800 UDIMM</a></li>
        </ul>
    </div>  
</div>

DDR3 memory mirroring – PCB layout

<div class="entry-content">
    <div class="jetpack-video-wrapper"><span class="embed-youtube" style="text-align:center; display: block;"><iframe src="https://www.youtube.com/embed/SxeW_-UcZqk" class="youtube-player" width="740" height="416.418" frameborder="0" allowfullscreen></iframe></span>
    </div>
    <div class="blog-content">
        This video explains how to generate a STEP file (3D output) from Altium Designer. It also explains how to add mounting holes into the 3D model.
    </div>
    <div class="blog-content-links">
        <div>
            Links:
        </div>
        <ul class="links-list">
            <li class="links-list-item"><a href="http://www.cadexchanger.com/">3D CAD software from this video (CAD Exchanger)</a></li>
        </ul>
    </div>  
</div>


Altium Designer – Generating 3D CAD File

<div class="entry-content">
    <div class="jetpack-video-wrapper"><span class="embed-youtube" style="text-align:center; display: block;"><iframe src="https://www.youtube.com/embed/QlNgoS3SEME" class="youtube-player" width="740" height="416.418" frameborder="0" allowfullscreen></iframe></span>
    </div>
    <div class="blog-content">
        This video explains how to do differential pair routing and how to setup rules for different impedances in Altium Designer PCB layout.
    </div>
</div>


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