This post is a continuation of my previous one and includes a table representation of the AVR ONE! JTAG pinout and a table describing which pins get connected from the AVR ONE! to the ATmega2560/Arduino.
JTAG Header Pinout
| Pin # | PinName | PinName | Pin # | |||
|---|---|---|---|---|---|---|
| 1[/center][/td][/td]TCK[/td][/td]GND[/td][/td]2[/td][/tr] 3[/center][/td][/td]TDO[/td][/td]VTref[/td][/td]4[/td][/tr] 5[/td][/td]TMS[/td][/td]nSRST[/td][/td]6[/td][/tr] 7[/td][/td]N.C.[/td][/td]nTRST[/td][/td]8[/td][/tr] 9[/td][/td]TDI[/td][/td]GND[/td]10[/tr] [/table] JTAG Pin Description Name Pin# AVR ONE! ATmega2560 Arduino TCK 1 Test Clock (clock signal from the AVR ONE! into the target device) Pin 93 - PF4 ( ADC4/TMK ) (A4) Analog pin 4 TMS 5 Test Mode Select (control signal from the AVR ONE! into the target device) PF5 ( ADC5/TMS ) (A5) Analog pin 5 TDI 9 Test Data In (data transmitted from the AVR ONE into the target device) PF7 ( ADC7/PCINT15 ) (A7) Analog pin 7 TDO 3 Test Data Out (data transmitted from the target device into the AVR ONE!) PF6 ( ADC6/PCINT14 ) (A6) Analog pin 6 nTRST 8 Test Reset (optional, only on some AVR devices). Used to reset the JTAG TAP controller nSRST 6 Source Reset (optional) Used to reset the target device. Connecting this pin is recommended since it allows the AVR ONE! to hold the target device in a reset state, which can be essential to debugging in certain scenarios. Pin 30 RESET VTref 4 Target voltage reference. The AVR ONE! samples the target voltage on this pin in order to power the level converters correctly. The AVR ONE! draws less than 1mA from this pin. Pins 10, 31, 61, or 100 VCC GND 2,10 Ground. Both must be connected to ensure that the AVR ONE! and the target device share the same ground reference. Pins 11,32, 62, 101, or 99 GND ***Please let me know if you spot anything that appears to be incorrect so I can keep this updated with accurate info. I would like to “keep it real” for anyone looking to this forum for answers. Edit 08/26/2012 corrected pin spec for nTRST (optional Test Reset) per hemmerling' observation |