Using AVR Studio

5-6 AVR STK500 User Guide

1925C–AVR–3/03

Figure 5-6. Board

5.3.5.1 VTARGET VTARGET controls the operating voltage for the target board. Through the use of the

slide bar or the text box, this voltage can be regulated between 0 and 6.0V in 0.1V incre-

ments. Please refer to the device datasheet to find the specified voltage range for the

selected device. Both voltages are read by pressing the “Read Voltages” button, and

written by pressing the “Write Voltages” button.

The physical connection of the VTARGET voltage is shown in Figure 3-22 on page 3-16.

5.3.5.2 AREF AREF controls the analog reference voltage for the ADC converter. This setting only

apply to devices with AD converter. Through the use of the slide bar or the text box, this

voltage can be regulated between 0 and 6.0V in 0.1V increments. Please refer to the

device datasheet to find the valid voltage range for the selected device. Both VTARGET

and AREF are read by pressing the “Read Voltages” button, and written by pressing the

“Write Voltages” button.

It is not possible to set AREF to a higher voltage than VTARGET because this will per-

manently damage the AVR.

The physical connection of the AREF voltage is shown in Figure 3-24 on page 3-18.

Using AVR Studio

AVR STK500 User Guide 5-7

1925C–AVR–3/03

5.3.5.3 Oscillator The STK500 development board uses a programmable oscillator circuit that offers a

wide range of frequencies for the target device.

Since it is not possible to generate an unlimited number of frequencies, the STK500

user interface will calculate the value closest to the value written to the oscillator text

box. The calculated value is then presented in the oscillator text box, overwriting the

previously written number.

5.3.6 “Auto” Settings When programming multiple devices with the same code, the “Auto” tab offers a power-

ful method of automatically going through a user-defined sequence of commands. The

commands are listed in the order they are executed (if selected). To enable a command,

the appropriate check box should be checked. For example, if only “Program FLASH” is

checked when the “Start” button is pressed, the Flash memory will be programmed with

the hex file specified in the “Program” settings. All commands depend on and use the

settings given in the STK500 user interface.

Figure 5-7. Auto

It is possible to log the command execution to a text file by checking the “Log to file”

check box.

Using AVR Studio

5-8 AVR STK500 User Guide

1925C–AVR–3/03

5.3.6.1 Setting Up the

System for

Auto-programming

Click on the check boxes for the commands that you want the STK500 user interface to

perform. A typical sequence where the device is erased and then programmed is shown

in Figure 5-7. The chip is erased, both memories programmed and verified, and finally,

fuses and lock bits are programmed.

Once configured, the same programming sequence is executed every time the “Start”

button is pressed. This reduces both work and possibilities for errors due to operational

errors.

5.3.6.2 Logging the

Auto-programming

to a File

By clicking on the “Log to file” check box, all output from the commands are written to a

text file. Select or create the file by pressing the “Browse” button and navigate to the

location where the file is placed or should be created. The output is directed to this file,

and can be viewed and edited using a text editor.

5.3.7 History Window The History window is located at the bottom of the STK500 view. In this window the dia-

log between AVR Studio and STK500 is shown. For every new command performed,

the old dialog is replaced with the new one.

Figure 5-8. History Window

Part #	C1925
Description	BLOCK, JUNCTION - Bulk
Category	HARDWARE
Availability	In Stock
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C1925

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