Assembling the NKC Electronics JTAG ICE CLONE Board (Rev. B)
by NKC Electronics
SCHEMATICS (right click –> view image)
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JTAG ICE Clone board is an implementation of the Aquaticus JTAG ICE clone. The Kit includes the PCB and all the parts requiered to build a fully functional clone of AVR JTAG ICE. It can even be upgraded using AVR-STUDIO when a new firmware is released by Atmel.
This guide covers the assembly process of the JTAG ICE clone Rev B kit (marked Rev B in the PCB)
First, unpack the kit and start with the PCB.
The JTAG ICE clone board has all the component values printed on the PCB, making the use of the schematic almost unnecessary.
We will install the passive components (resistors, capacitors, etc) first.
Start by soldering the resistors R1 to R7, C3 to C9 ceramic capacitors, C10 electrolytic capacitor and D2 diode
| R1 | 10 K resistor |
| R2, R3, R4, R6 | 1 K resistor |
| R5, R7 | 4.7 K resistor |
| C3, C4, C5, C6, C7, C8, C9 | 0.1uF ceramic capacitor |
| D1 | 1N4148 diode |
| C10 | 10uF electrolytic capacitor |
Next identify and separate the 2 22pF ceramic capacitors, 2 LEDs and the crystal
| C1, C2 | 22pF ceramic capacitor |
| Q1 | 7.3728 crystal |
| PWR, JTAG | 3mm LED |
Now separate the 16-pin IC socket, 40-pin IC socket (wide), 10-pin male header, 5-pin male header, DB9 female PCB connector. Cut the 5-pin male header in one 3-pin header and one 2-pin header.
| X1 | DB9 female PCB connector |
| JTAG | 2×5 male header |
| IC1 | 40-pin DIP socket |
| IC2 | 16-pin DIP socket |
| JP1 | 3-pin male header |
| JP2 | 2-pin male header |
We are done with the soldering. You need to install the MCU and the RS232 (ICL3232, MAX3232, ST3232) driver in the sockets. The large chip is the ATMEGA16 Microcontroller. It is already programmed with the latest release of the JTAG ICE firmware, and the bootloader. Please, be very careful with the pins while inserting the ICs.
Insert the shunt shorting positions 2-3 of the 3-pin MODE header. The JTAG ICE clone board has two modes of operation:
- Programming / Upgrade mode
- Normal operation mode
Position 2-3 is the Normal operation mode (board is ready to connect to target board and start debugging)
Position 1-2 is the Programming mode. This mode is used to program or upgrade the JTAG ICE firmware. The firmware is distributed by Atmel with updates on the AVR Studio IDE. In the operation guide you will find the manual firmware upgrade process, explained in detail.
This is how the JTAG ICE clone board looks ready to use with the 10-wire cable for the target board.
The target board must supply the power to the JTAG ICE clone board, using the standard JTAG connector. The board expects the power from the target board (2.7V to 5.0V) in the VTarget (VCC) pin. It is recommended to supply also the target voltage to the VTref pin (Use the provided JP2 and jumper to supply power to the board from the target device). The JTAG ICE board does not have voltage leveling circuit, so if you supply VTref, it must be the same as VTarget.
Testing the board:
- Start AVR Studio
- Verify mode jumper is in 2-3 Normal
- Connect JTAG port to target board. Supply VCC. At this point, you only need to supply VCC to the JTAG ICE clone board. No real circuit with target MCU is needed
- Both LEDs are on
- Select Connect to the Selected AVR Programmer
- You should see the following message:
This message means that AVR Studio detected the JTAG ICE clone board, but was not able to identify the target MCU (either it is not installed, or the installed MCU does not support JTAG).
The JTAG ICE clone board is now assembled and tested. Now you need a real target board to start debugging.
An important reminder: JTAG ICE requieres the JTAG fuse in the target MCU set: JTAG Interface Enabled [JTAGEN=0]. The setting looks like this in AVR Studio:
IMPORTANT NOTE to AVRStudio 4.13 sp2 users: There seems to be a bug in AVRStudio 4.13 sp2 that generates an error trying to read fuses using the JTAG interface. There is a fix posted in Atmel Norway website: http://www.atmel.no/beta_ware/as4/413sp2/stk500Dll.zip
