Teensy

The heart of the USB+ interface is a Teensy 4.1 USB Development board from PJRC. This module is powered by a Cortex-M7 dual-issue superscaler processor and is clocked at 600MHz. It provides a USB interface which operates at 480 Mbit/sec.

Some other features:

  • Floating point math unit, 64 & 32 bits

  • 7936K Flash

  • 1024K RAM (512K tightly coupled)

  • 4K EEPROM (emulated)

  • 55 digital input/output pins, 35 PWM output pins

  • Ethernet 10/100 Mbit with DP83825 PHY

  • RTC for date/time

  • 1 SDIO (4 bit) native SD Card port

  • Cryptographic Acceleration & Random Number Generator

Why a Teensy 4.1?

The communication handshake of the P7001 is a multi-stage design which is very complex. 10 dedicated handshake lines are involved. In the original CP-Bus Interface almost 20 ICs are responsible for this job.

I wanted to reduce the hardware to an absolute minimum. I found the Teensy 4.1 USB development board to be ideal for designing the USB interface. It’s fast, has a lot of IO pins and comes with two ready to use USB ports. Another important point is that there are at least two different free-to-use development environments available.