Teensy 4.0 Schmatic wrong?

B

bigboosted

Well-known member
I bought several windbond spi memory chips based on the part number on the schematic; W25Q64JVXGIM however what came dose not match what's on the teensy board.

When I looked up the manual the part number references a package code XG = XSON 4x4x0.45-mm, the chip on the teensy board is more like 3x2x0.45mm
So what is the actual part number of the chip on the Teensy 4.0?

I am looking to add my own restore program to the memory and the chip included on teensy has that restore part of the chip's memory permanently locked.

And as long as I'm asking I see the new 4.1 has 4 times the memory and a bigger footprint. What's the part number on that one also?

Thanks


I'm guessing the 4.0 chip should have a package code UX = 8-pad USON 2x3-mm ??
 
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Oh! I messed that up. I guess I have some memory chips for the new 4.1

Dose the 4.1 also have a locked restore program area?
 
Yes, Teensy 4.1 has basically the same restore program in its top 4K of the flash chip.

Why are you trying to change the restore program? What do you hope to accomplish?
 
PaulStoffregen said:
Yes, Teensy 4.1 has basically the same restore program in its top 4K of the flash chip.

Why are you trying to change the restore program? What do you hope to accomplish?
Click to expand...

I use teensy in an outdoor product that is sealed in potting. I don't leave access to the USB. Only can bus. I already have firmware updates by can in place but if an update would happen to fail I want to use this restore program feature to reload a new file via can bus instead of USB.

I emailed you a while ago about this and didn't get a response, I asked for some teensy 4.0s with an unlocked memory chip. I figured you were busy with all the shelter in place and new products.
 
Maybe it is cheaper in this case to just replace the teensy with a new one. Saves time for development and other resources. Just a suggestion :)
 
Frank B said:
Maybe it is cheaper in this case to just replace the teensy with a new one. Saves time for development and other resources. Just a suggestion :)
Click to expand...

That would take all the fun out of it! Not to mention the rest of the stuff the teensy is attached to is very expensive. The other hardware justifies my time in making this device theoretically unbrickable.


I just ordered the correct chips. Should be here this week yet! Thanks for the clarification, Paul!
 
I am building a custom Teensy 4.1 board. W25Q64JVXGIM seems to be having availability problems. I know that the documentation says that the "Q" part numbers are not compatible. Has anyone had success with any of the following:
W25Q64JVSSIM
W25Q64JWZPIM
W25Q64JVZEIMS
W25Q64JWSSIM
W25Q64JVSFIM
 
Any 2 letters between "JV" and "IM" should work, as those 2 letters are merely the package type. They are exactly the same silicon inside, simply put into a different plastic package. So W25Q64JVSSIM and W25Q64JVSFIM should be the same as the W25Q64JVXGIM chip used on Teensy 4.1. Obviously the physical shape is different, so be careful to design your PCB and check the fit (as with all PCB design....)

The "JW" parts definitely will not work. Do not use W25Q64JWZPIM or W25Q64JWSSIM. Only use "JV" parts.

I don't know about W25Q64JVZEIMS. I'm not familiar with the meaning of "S" on the end.
 
Ok, perfect. Parts are getting hard to find. While I have your attention, the 32.767kHz crystal is showing 20pf capacitors on your schematic. Are you sure that is correct? The highest capacitance crystals in that frequency seem to be 12.5pf.
 
Yes, correct.

Crystal oscillators use total capacitance on each pin twice the rating of the crystal (because the 2 capacitors are effectively in series relative to the crystal). Pin has approx 5pF, so 20pF is indeed correct capacitor to use.
 
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