Product Description
Lockable Teensy 4.0 features an ARMCortex-M7 processor at 600MHz, with a NXP iMXRT1062 chip. Teensy 4.0 is the same size and shape as Teensy 3.2, and retains compatibility with most of the pin functions on Teensy 3.2. For commercial products and secure applications
When running at 600 MHz, Teensy 4.0 consumes approximately 100mA current. Teensy 4.0 provides support for dynamic clock scaling.
The ARM Cortex-M7 brings many powerful CPU features to a true real-time microcontroller platform. Cortex-M7 is a dual-issue superscaler processor, meaning the M7 can execute two instructions per clock cycle, at 600MHz!
- ARM Cortex-M7 at 600MHz
- 1024K RAM (512K is tightly coupled)
- 2048K Flash (64K reserved for recovery & EEPROM emulation)
- 2 USB ports, both 480MBit/sec
- 3 CAN Bus (1 with CAN FD)
- 2 I2S Digital Audio
- 1 S/PDIF Digital Audio
- 1 SDIO (4 bit) native SD
- 3 SPI, all with 16 word FIFO
- 3 I2C, all with 4 byte FIFO
- 7 Serial, all with 4 byte FIFO
- 32 general purpose DMA channels
- 31 PWM pins
- 40 digital pins, all interrrupt capable
- 14 analog pins, 2 ADCs on chip
- Cryptographic Acceleration
- Random Number Generator
- RTC for date/time
- Programmable FlexIO
- Pixel Processing Pipeline
- Peripheral cross triggering
- Power On/Off management
- Pre-soldered Male Headers
Code Security
Program Memory Protection
- Code security protects your program code from unauthorized access and coping. When compiling, your program is encrypted. When run, the IMXRT Bus Encryption Engine provides on-the-fly decryption as your program executes. If an attacker removes and reads the flash memory chip from Teensy 4.1, or attempt to capture the USB communication from Teensy Loader, or copies the EHEX file Teensy Loader opens, they get only an encrypted copy of your program.
Secure Firmware Update
- Users can be given an EHEX file and Teensy Loader to securely update commercial products or secure applications which embed a Lockable Teensy, without gaining access to the original program code. Of course the key already in its fuse memory and secure mode locked when the product is shipped.
Permanent Secure Mode
- Brand new Teensy 4.1 can only run unencrypted programs. Once a key is written into fuse memory, either encrypted or unencrypted programs can run. Secure mode permanently disables the ability to run unencrypted code, and activates hardware security features.
Lockable Teensy
- Secure mode can only be activated on Lockable Teensy. While Standard and Lockable Teensy are identical hardware, the permanent fuse configuation differs. Standard Teensy does not allow changes to fuses affecting boot or other critical configuration. Standard Teensy is meant to safe from "bricking" by programs which could write to fuse memory, but this safety means secure mode can not be activated. Standard Teensy can have a key written and can run encrypted code, but encryption alone is not fully secure. Only Lockable Teensy provides proper code security, and only when a key is written and secure mode is locked.
Authentication
- The encryption process includes digital signature authentication. In secure mode, this signature is checked before any code can be decrypted.
JTAG Disable
- Secure mode permanently disables the JTAG port. To enter programming mode without JTAG, Teensy Loader and the EHEX file automatically utilize a loader utility which is authenticated by your key's digitial signature, and in turn uses secure hash checks to fully authenticate all components of the programming process.
EHEX File Format
- Teensyduino packages your encrypted code, metadata, a startup shim, loader utility, digital signatures and other essential details into a single EHEX file. This EHEX may be given to customers or untrusted parties to perform code updates with the convenice of a single file. The EHEX format and encryption details are documented on the code security page
Key Management
- To make creating and using your key simple, Teensyduino adds a "Teensy 4 Security" window to the Arduino Tools menu. These functions can also be accessed from a command line utility for use from non-Arduino tools or automated scripts.
