Teensy 4.1

DEV-16771

The Teensy 4.1 is the newest iteration of the astoundingly popular development platform that

features an ARM Cortex-M7 processor at 600MHz, with a NXP iMXRT1062 chip, four times larger

flash memory than the 4.0, and two new locations to optionally add more memory. The Teensy 4.1 is

the same size and shape as the Teensy 3.6 (2.4in by 0.7in), and provides greater I/O capability,

including an ethernet PHY, SD card socket, and USB host port.

When running at 600 MHz, the Teensy 4.1 consumes approximately 100mA current and provides

support for dynamic clock scaling. Unlike traditional microcontrollers, where changing the clock

speed causes wrong baud rates and other issues, Teensy 4.1 hardware and Teensyduino's software

support for Arduino timing functions are designed to allow dynamically speed changes. Serial baud

rates, audio streaming sample rates, and Arduino functions like delay() and millis(), and

Teensyduino's extensions like IntervalTimer and elapsedMillis, continue to work properly while the

CPU changes speed. Teensy 4.1 also provides a power shut off feature. By connecting a pushbutton

to the On/Off pin, the 3.3V power supply can be completely disabled by holding the button for five

seconds, and turned back on by a brief button press. If a coin cell is connected to VBAT, Teensy

4.1's RTC also continues to keep track of date & time while the power is off. Teensy 4.1 also can

also be overclocked, well beyond 600MHz!

The ARM Cortex-M7 brings many powerful CPU features to a true real-time microcontroller platform.

The Cortex-M7 is a dual-issue superscaler processor, meaning the M7 can execute two instructions

per clock cycle, at 600MHz! Of course, executing two simultaneously depends upon the compiler

ordering instructions and registers. Initial benchmarks have shown C++ code compiled by Arduino

tends to achieve two instructions about 40% to 50% of the time while performing numerically

intensive work using integers and pointers. The Cortex-M7 is the first ARM microcontroller to use

branch prediction. On M4, loops and other code which much branch take three clock cycles. With

M7, after a loop has executed a few times, the branch prediction removes that overhead, allowing

the branch instruction to run in only a single clock cycle.

Tightly Coupled Memory is a special feature which allows Cortex-M7 fast single cycle access to

memory using a pair of 64 bit wide buses. The ITCM bus provides a 64 bit path to fetch instructions.