Teensy 4.1 without Ethernet, Lockable

Meet the Lockable Teensy 4.1 without Ethernet. This board combines the high-performance, expanded memory of the 4.1 with production-grade code security, all in a streamlined package without the Ethernet PHY. It’s designed for secure, large-scale projects that don't require wired networking. Featuring a similar NXP processor, this board is built around an ARM Cortex-M7 processor running at 600 MHz. This power is supported by 8MB of Flash memory (four times larger than the 4.0) and 1MB (1024K) of RAM.

This board adopts the larger Teensy 3.6 form factor (2.4in x 0.7in) and provides significant I/O capability. While it omits the Ethernet controller for a more streamlined design, it retains the other powerful features of the 4.1, including a built-in microSD card socket and a USB host port. Please note that this board does not include headers; they must be purchased and soldered separately.

Production-Grade Code Security

This Lockable version of the Teensy 4.1 is intended for developers who are ready to move from prototype to a final, secure product. While a standard Teensy is "unbrickable" and ideal for development, this model provides write access to the chip's eFuses, allowing you to lock the device into a secure mode permanently.

Once you program your unique encryption key and lock the device, your application code is encrypted. This prevents unauthorised reading, cloning, or modification of your intellectual property. In secure mode, the JTAG debug port is permanently disabled, and the microcontroller will only run code that has been encrypted with your private key.

Warning: This is a one-way, irreversible process. This board is for advanced users finalizing a product. Setting the fuses incorrectly can permanently "brick" the device. For all development and prototyping, please use the standard Teensy 4.1.

The Power of the Cortex-M7 Core

At the heart of the Teensy 4.1 is the NXP MIMXRT1062DVJ6B, a "Crossover MCU" engineered to bridge the gap between low-cost microcontrollers and high-performance application processors. While it features the same powerful 600 MHz ARM Cortex-M7 core as the Teensy 4.0, this version uses a larger 196-pin package. This expanded pinout is the key to the Teensy 4.1's massive feature set, allowing it to break out all the extra I/O, the SDIO interface, and the USB Host port that the smaller package cannot.

• Dual-Issue Superscalar Processor: The M7 isn't just fast; it's efficient. It can execute two instructions per clock cycle at 600 MHz. Benchmarks show C++ code compiled by Arduino can achieve this dual-instruction execution 40-50% of the time, dramatically accelerating numerically intensive work.
• Branch Prediction: This is the first ARM microcontroller to use branch prediction. Where other microcontrollers (like the M4) waste three clock cycles on loops, the M7's branch predictor learns the loop and removes that overhead, allowing the branch instruction to run in a single clock cycle.
• Hardware FPU: The built-in Floating Point Unit (FPU) crushes maths operations. Unlike many microcontrollers that only accelerate 32-bit floats, the Teensy 4.1's FPU provides full hardware acceleration for both 64-bit "double" and 32-bit "float" types. Complex functions like log(), sin(), and cos() are executed at full hardware speed, not through slow software emulation.

Advanced & Expandable Memory Architecture

To keep the 600 MHz CPU fed with data, the Teensy 4.1 utilizes Tightly Coupled Memory (TCM). This special feature allows the Cortex-M7 to use 512K of its 1024K total RAM as incredibly fast, single-cycle access memory via a pair of dual 64/32-bit high-speed buses (one for instructions, one for data).

The Teensyduino environment automatically allocates your sketch code into this blazing-fast memory. This high-speed access is separate from the main AXI bus, allowing powerful DMA-based peripherals to access other memory with excellent efficiency, thereby minimising I/O bottlenecks.

In addition to the ample onboard memory, the Teensy 4.1 also features two new locations on the bottom of the board for optional soldering of external memory, allowing you to add up to 16MB of PSRAM or a QSPI flash chip for even larger applications.

Smart Power Management & Flexibility

The Teensy 4.1 is powerful, yet efficient, consuming approximately 100mA when running at 600 MHz.

• Dynamic Clock Scaling: You are not locked into one speed. The Teensy 4.1 provides full support for dynamic clock scaling. Unlike traditional microcontrollers, changing the CPU speed on the fly will not break your serial baud rates, audio streaming sample rates, or Arduino timing functions like delay() and millis().
• Power On/Off: For low-power or battery-operated projects, a dedicated On/Off pin allows you to completely disable the 3.3V power supply. Simply connect a pushbutton and hold it for five seconds to power down. A brief press turns it back on.
• RTC Support: If a coin cell is connected to the VBAT pin, the Teensy 4.1’s Real-Time Clock (RTC) will continue to keep track of date and time even when the main power is off.
• Overclocking: For those who push the limits, the Teensy 4.1 is also capable of being overclocked well beyond 600 MHz!

With the processing speed of the Cortex-M7 combined with expanded memory and essential peripherals like a built-in SD slot and USB host port, this Teensy 4.1 is the ideal solution for high-performance projects that don't require network connectivity.

Note: You can find information about code security & lockable Teensy here.

• Manual (MIMXRT1062 DVJ6B)
• Datasheets
  • MIMXRT1062 DVJ6B
  • W25Q64JV-DTR Flash
• Teensy Quick Start
• Teensyduino Software
• Teensy Help Page and FAQ
• Teensy Compliance Documentation
• Code Security & Lockable Teensy
• Reference Manuals:
  • ARM Cortex-M7
  • ARM v7-M Architecture