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Thread: Teensy 4.0 external memory

  1. #1
    Junior Member
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    Teensy 4.0 external memory

    Hi,

    I am a working on a project which requires a fairly large buffer (~40MB) to temporarily store the data.

    I think the best option would be an SDRAM chip (something like this: https://www.mouser.co.uk/ProductDeta...n3dqXLk4ebc%3D), however, since it has a lot of pins, I am not sure if Teensy 4.0 can handle it (or me for that matter since I have no experience with this).

    Another option I found is flash memory with Quad SPI (something like this: https://www.mouser.co.uk/ProductDeta...sHZp0BRA%3D%3D). Which seems a bit easier to implement (or at least the single SPI mode is), but I am not sure if it is possible to use Quad SPI on Teensy 4.0?

    From the microcontroller datasheet:
    External memory interfaces:
    — 8/16-bit SDRAM, up to SDRAM-133/SDRAM-166
    — 8/16-bit SLC NAND FLASH, with ECC handled in software
    —SD/eMMC
    — SPI NOR/NAND FLASH
    — Parallel NOR FLASH with XIP support
    — Two single/dual channel Quad SPI FLASH with XIP support
    So I think both of those would be supported with the i.MX RT1062 I am just not sure if the Teensy 4.0 has all the required pins exposed?

    Has anyone here done something like this before and could share some advice/documentation/example code to do it?

  2. #2
    Senior Member PaulStoffregen's Avatar
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    Quote Originally Posted by Titas22 View Post
    I am just not sure if the Teensy 4.0 has all the required pins exposed?
    Sadly, no, Teensy 4.0 does not bring out all the pins needed.

  3. #3
    Junior Member
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    Quote Originally Posted by PaulStoffregen View Post
    Sadly, no, Teensy 4.0 does not bring out all the pins needed.
    Thanks, will keep that in mind. Would you be able to suggest any alternative solutions? My main requirement is 40MB+ and I am looking for the fastest option that can give me that (in terms of write/read speeds).

  4. #4
    Senior Member+ defragster's Avatar
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    With connection of the USB Host device pins on the T_4 an external Flash drive or HDD writes to those device can work at 8+ MB/sec with GB's of available storage. An SD socket properly wired to the SDIO pins could likewise provide generous storage at similar rates.

    A couple of available breakout DIY PCB's offer ways to connect to either of those interfaces in some fashion. Paul published the hardware used in the T_4. Beta and there are boards like TallDog/@LOGLOW's ( still in Beta ) and the FRDM4236 board and some simple OSHPark PCB's posted and linked. There is a thread for the USBHost_T36 that was co-developed with T_4.0 through beta showing the software and results in use.

    Thread: USBHost_t36-USB-Mass-Storage-Driver-Experiments

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