 The JTAGICE mkI is no longer in production, however it has been replaced by the JTAGICE mkII.The JTAGICE mkII debugging tool supports on-chip debugging (OCD) of AVRs with SPI, JTAG, PDI, and debugWIRE interfaces.The debugWire interface enables debugging using only one pin (the Reset pin), allowing debugging of applications running on low pin-count microcontrollers.