14

AVR069

8015B-AVR-02/06

Bit value

Status

0x04

STATUS_CONN_FAIL_SCK

0x10

STATUS_TGT_NOT_DETECTED

0x20

STATUS_TGT_REVERSE_INSERTED

0x00

STATUS_ISP_READY

The corresponding bit will be set ‘1’ to indicate an error.

That is, if a line is short-circuited, if target is not detected or the plug is inserted with a

reverse orientation.

If the value 0x00 is returned it means the connection is ok.

If any *_CONN_FAIL_* bit is set, the command CMD_RESET_PROTECTION must

be issued.

The parameter should be checked before starting a programming sequence to check

if target connection is correct.

It should also be checked after a programming sequence if the command failed to

check if the operation failed because of a short circuit.

A short circuit can only be detected after the command Enter Progmode has been

issued, because the control circuits of the AVRISP mkII is isolated via switches when

the AVRISP mkII is in idle mode.

3.4.10 PARAM_DISCHARGEDELAY

This parameter sets a time period for which the reset line has a higher resistance for

each time it is toggled.

The purpose is to reduce the maximum current caused by the discharge/recharge of

a decoupling capacitor connected to the reset pin.

When the reset is toggled a resistor of 510ohm will be switched in, which reduces the

peak current to an acceptable level for the internal components of the AVRISP mkII.

The delay should be set to: t>510ohm*C

If no capacitor is connected this parameter could be set to 0.

4 XML Parameter Values

The AVRISP mkII firmware uses parameters extensively for its programming

algorithms. All AVR devices have their own set of parameters. They can be found in

part description files installed with AVR Studio. The part description files are XML files

and can be found in the folder

… \Atmel\AVR Tools\PartDescriptionFiles\