Call to arms | Teensy + SDRAM = true

another suggestion - can the On/Off pin be moved as well next to the Boot button? 😅😆
What is the on/off pin for even, maybe remove it?

Anyway, here it is!

1717272890744.png
 
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Yes, alternate pins for CAN FD, very good for the future.
KurtE can you give me pin numbers for these two last additions?
Two options:
a) Easy - make them the next two pin numbers so 68, 69
b) slight more work - make them 64, 65, and update the current 64... numbers on that side to +2 so 66, 67...

Either works for me
 
Its been a while. I think without a cap you are only going to get to about 198Mhz. (not sure about that value since its been a while). Not sure you want to go faster than that though since that is way over the spec anyway's
It has indeed been a while. Even tho I did allot of testing, I am unsure what we should do here.
 
@Dogbone06 the new board looks great!
As we spoke privately - adding in two more pins for CAN3 (CAN DF) connectivity.
Pins GPIO_AD_B0_15 and GPIO_AD_B0_14 @KurtE heads up
Sorry been out of pocket for awhile so just catching up. Cool you added CAN-FD. @tonton81's lib does support alt can pins so nice you added them
 
It has indeed been a while. Even tho I did allot of testing, I am unsure what we should do here.
Just add the pads, and not populate?
Then if thought needed in the future it is easy to add.
That is as long as open pads and traces are not going to compromise anything.
 
Nice - I see B0_ and B1_ came to a linear ordering!

CAP values - not again :) - Indeed only needed to OC beyond reasonable - seems 12-13 pF was safe to get into low 200 MHz's reliably - not sure if better open or some safe fixed known value - that may not be that same with other wires around.

Still two USB Device input connectors? Not seeing label for USB-Host - did that get brought out? A lot else going on and just more sensitive wires.
 
Printed the board image - glancing at the 5V and 3.3V group sections the ' - ' dashes for '...' look like MINUS ... like the GND beside them.

Of course it isn't "-5V" ... but would ' + ' make more sense and not break any silkscreen rule?

Code:
[ + 5V + ]

and the other corner twice

[ + 3.3V + ]
 
I took the easy route. I usually put pin numbers as defines and name them.

So I'm ready to order if no one has any objections?
View attachment 34534
I updated the excel document to match the update... probably more of the usages of the pins can and should be double checked...

No objections from me... Note: I could probably never run out of things to ask for, but ...

Still two USB Device input connectors? Not seeing label for USB-Host - did that get brought out? A lot else going on and just more sensitive wires.
I believe you have host stuff working on the 4.5. Probably need in most cases use a USB3 to USB2... cable, but that is the way things are going anyway...

In all of my boards where I put USB connectors on, I usually add places I can solder in pins for USBH+ and USBH- and if I actually made a board like this with it's own USB in, I would also add easily places to connect to the + and - signals as well. That way I can monitor the USB communications using Saleae LA, at least for USBLS and USBFS... It can not do USBHS or ...

But I would not hold up things up for this...
 
About the DQS cap... assuming it's not too late and Dogbone hasn't done the order already, looking back over the testing I would suggest using a 10pf cap rather than just the floating trace. We do know that it is sensitive to length, and there is a (small) chance that getting rid of the pad might reduce the capacitance enough to throw out timing at 166MHz and above - we just don't know. But we do know that a 10pf works well up to around 240MHz, which is why I'm suggesting it.
 
* USB Host is present already and working. With USB Power Delivery available as well as a choice. By soldering 2 of 3 pads you can have either 5V (from the first USB input) or USB PD where you have to provide external power.

* The [ — 5V — ] is just a way to show that several pins are the same instead of putting many labels. The — does not represent minus.

* So I’ll place the 10pF cap then correct?
 
Yes, 10 pF cap seems a safe bet if the wires end up with similar behavior. Just put a fresh 10 pF on DevBd 4.0 here and:
Code:
Test summary: 57 tests with 5 ReReads at F_CPU_ACTUAL 600 Mhz:
     At 166 MHz in 145 seconds with 0 read errors
     At 196 MHz in 136 seconds with 0 read errors
     At 206 MHz in 133 seconds with 0 read errors
     At 216 MHz in 132 seconds with 0 read errors

    SDRAM One Scan CAP test Complete {v1.4} :Note tested CAP here pF=
** Alternate run shows 227 MHz to work and seeing fails at 240 MHz
Code:
     At 216 MHz in 132 seconds with 0 read errors
     At 227 MHz in 128 seconds with 0 read errors
     At 240 MHz in 127 seconds with 784 read errors (0.0000%)
* The [ — 5V — ] is just a way to show that several pins are the same instead of putting many labels. The — does not represent minus.
Indeed, understood that is the intent - was just noting the '-' is right by the '---' GND symbols and a '+' there would provide a clearer delineation of the transition - given parallax to header top and less than ideal eyesight
* USB Host is present already and working
Good. As noted - not able to 'read' the intent of micro-SilkScreen: two USB C connectors - but central one is now USB Host not a duplicate of Device USB as on DevBoard 4?
.
 
Yes, 10 pF cap seems a safe bet if the wires end up with similar behavior. Just put a fresh 10 pF on DevBd 4.0 here and:
Code:
Test summary: 57 tests with 5 ReReads at F_CPU_ACTUAL 600 Mhz:
     At 166 MHz in 145 seconds with 0 read errors
     At 196 MHz in 136 seconds with 0 read errors
     At 206 MHz in 133 seconds with 0 read errors
     At 216 MHz in 132 seconds with 0 read errors

    SDRAM One Scan CAP test Complete {v1.4} :Note tested CAP here pF=
** Alternate run shows 227 MHz to work and seeing fails at 240 MHz
Code:
     At 216 MHz in 132 seconds with 0 read errors
     At 227 MHz in 128 seconds with 0 read errors
     At 240 MHz in 127 seconds with 784 read errors (0.0000%)

Indeed, understood that is the intent - was just noting the '-' is right by the '---' GND symbols and a '+' there would provide a clearer delineation of the transition - given parallax to header top and less than ideal eyesight

Good. As noted - not able to 'read' the intent of micro-SilkScreen: two USB C connectors - but central one is now USB Host not a duplicate of Device USB as on DevBoard 4?
.
* I’ll put the 10pF back

* I’ll remove — and replace with spaces instead.

* Yes correct, I’ll see if there’s space for text to say it’s host.
 
One very minor thing (don't kill me): looking at the USB Host power, should the 5V be taken from the other side of the diode? Since otherwise if the board is powered directly via the 5V pins (without a PC connected to the USB), the USB host port will not get power (unless an external PD supply is used).
It means the USB Host power will be slightly below 5V (because of the diode drop) but looking at the T4 schematic, that's how it does it...
 
One very minor thing (don't kill me): looking at the USB Host power, should the 5V be taken from the other side of the diode? Since otherwise if the board is powered directly via the 5V pins (without a PC connected to the USB), the USB host port will not get power (unless an external PD supply is used).
It means the USB Host power will be slightly below 5V (because of the diode drop) but looking at the T4 schematic, that's how it does it...
You are indeed right about the diode, in some sense. The diode adds some protection. So yes it's a good idea to take the power after the diode.
USB-HOST has 3 pads. Solder 2 of them to get either 5V from the USB input. Or solder the other 2 pads to enable USB-PD where you have to provide your own 8 - 32V input via the screw terminal.

Is that what you meant?
 
You are indeed right about the diode, in some sense. The diode adds some protection. So yes it's a good idea to take the power after the diode.
USB-HOST has 3 pads. Solder 2 of them to get either 5V from the USB input. Or solder the other 2 pads to enable USB-PD where you have to provide your own 8 - 32V input via the screw terminal.

Is that what you meant?
Yes. I can't read the writing on the 3 pads so I'll refer to the one connected to the diode anode as pad 1. I think it should be connected to the diode cathode instead, so that USB Host still gets power when the board is powered by 5V supply rather than a PC USB connection.

If the voltage drop (from the diode) on the USB Host power turns out to be an issue for anyone, they could solder a bodge wire from pad 2 (the middle pad) to the diode anode, instead of bridging pads 1+2.
 
Yes. I can't read the writing on the 3 pads so I'll refer to the one connected to the diode anode as pad 1. I think it should be connected to the diode cathode instead, so that USB Host still gets power when the board is powered by 5V supply rather than a PC USB connection.

If the voltage drop (from the diode) on the USB Host power turns out to be an issue for anyone, they could solder a bodge wire from pad 2 (the middle pad) to the diode anode, instead of bridging pads 1+2.
I am not entirely sure I follow. Let's see if this helps.

Blue and Green are two different scenarios.
1717320791461.png
 
Ok for the case where the GREEN linked pads are bridged: imagine the board is being powered by 5V direct to one of the broken out 5V pins, with nothing connected to the (non-host) USB port. There will be no voltage on USB_VIN so USB_VIN1 will get no power. But if it was connected to the other side of the diode it would be getting the 5V.
 
Ok for the case where the GREEN linked pads are bridged: imagine the board is being powered by 5V direct to one of the broken out 5V pins, with nothing connected to the (non-host) USB port. There will be no voltage on USB_VIN so USB_VIN1 will get no power. But if it was connected to the other side of the diode it would be getting the 5V.
I see it now, that's a very good catch! I'll fix that!

EDIT: Fixed!

1717321547185.png
 
EasyEDA JSON files, import these into EasyEDA to gain full editorial control over both PCB and Schematic.
But there's also Gerber, Pick and Place and BOM file in there.

NOTE: At this point we have no idea if the board works. Using the Gerbers to order one of these is risky.

 
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