Board Description / Headers

AVR Dragon Board:

Headers:

Out of the box, the AVR Dragon has the following 3 header connectors mounted:

 

 

The following header are not mounted

ISP Header (mounted):

This 6-pin header uses the standard AVR ISP pinout for easy connection to external targets. The signals are level-converted to allow communication with targets running at any voltage between 1.8 and 5.5V

 

Note that the target voltage must be applied to pin 2 on the ISP header for the AVR Dragons level converters.

 

 

 

JTAG Header(mounted):

The 10-pin JTAG header is a standard pinout JTAG connector. When connecting the AVR Dragon JTAG header to an external target, the signals are level converted to match the target board voltage. This is done automatically. Please note that the AVR Dragon will not power the target through the JTAG interface. The target needs to be powered through a dedicated powersupply. (or by powering it using the VCC connector (5.0V max 300mA). AVR Dragon needs to sense the target voltage on pin 4 on the JTAG connector.

 

 

Pin

Signal

I/O

Description

1

TCK

Output

Test Clock, clock signal from AVR Dragon to target JTAG port

2

GND

-

Ground

3

TDO

Input

Test Data Output, data signal from target JTAG port to AVR Dragon

4

VTref

Input

Target reference voltage. VDD from target used to control level-converter

5

TMS

Output

Test Mode Select, mode select signal from AVR Dragon to target JTAG port

6

nSRST

In/Out-put

Open collector output from adapter to the target system reset. This pin is also an input to the adapter so that the reset initiated on the target may be reported to the AVR Dragon

7

-

-

Not connected

8

-

-

Not Connected

9

TDI

Output

Test Data Input, data signal from AVR DragoI to target JTAG port

10

GND

-

Ground

 

 

HV_PROG Header (not mounted):

The HV_PROG connector contains all signal required to do HVSP or PP programming. The signals on this connector is not level-converted, and should only be connected to the EXPAND connector on the AVR Dragon. You could damage both your target and the AVR Dragon if you try to do HVSP or PP on an external target board. The signal levels on the HV_PROG header are 5V.

 

 

The figure above shows the general pinout of the HV_PROG header. The High Voltage programming pin mapping are not the same for all parts. See the HVSP Description or PP Description  chapters for more information on the pinout of this header.

 

VCC Header (mounted):

 

The VCC Header contains 5.0 Volt VCC and GND that must be used to power the target device placed in the prototype area of the AVR Dragon board. The voltage can also be used to power an external target board, but it is important that the current consumption is less than 300mA. Please note that the AVR Dragon current sourcing capabilities are also limited by the amount of current the Host USB controller can deliver.

 

EXPAND Header (not mounted):

The expand connector is directly mapped to the 28 and 40-pin DIP sockets. Pin 1 on the connector - is pin one on both the 28 and the 40pin DIP socket. When doing either programming or emulation on-board, the appropriate signals should be routed from the ISP, JTAG, VCC and HV_PROG headers to the correct pins on the EXPAND connector. Please read the "Using the AVR Dragon Prototype Area" section for more information on how to use this function.

 

Status LEDs

 

Two LEDs show the status of the AVR Dragon. Check the Troubleshooting Guide to check for solutions if there are any errors.

 

LED #

Color

Description

2

Green

Indicates USB traffic

1

Red

Idle, not connected to AVR Studio

Dark

Idle, connected to AVR Studio

Green

Data Transfere

Yellow

Firmware Upgrade or Initialization