The new devices are available in 32-pin packages, including a tiny 5 x 5 mm QFN package. Despite the small size packages, they offer 21 general purpose IOs that can be used to detect interrupts. This avoids the need for multiplexing techniques or more expensive workarounds to overcome interrupt pin limitations of other USB controllers. Fast wake up times are achieved with low power consumption through a finely stepped sleep and watchdog timer. The devices operate from a 2.7 to 5.5V input.
The AT90USBKEY Demo Kit is a fast-start option and evaluation and debugging tools are also available now. The ATSTK526 Development Kit can be used in stand-alone form to demonstrate HID, communication device class (CDC) and mass storage. It can also be used as an extension to the generic STK500. The JTAGICE mkII and AVR Dragon can connect to the starter kit for in-system programming and emulation through on-chip debug resources (OCD). All of the kits are available ex-stock from Nu Horizons.