ULINK: ULINK-ME FAILS WITH ACTEL SMARTFUSION BOARDS

Information in this article applies to:

• ULINK-ME Vers.4

SYMPTOM

Debugging SmartFusion boards using a ULINK-ME does not work when the board is powered up while ULINK-ME is connected. If the board is powered up first and ULINK-ME is connected afterwards debugging works correct.

CAUSE

ULINK-ME is designed to supply 3.3V power to the target system. But the SmartFusion board needs different voltages and higher currents than ULINK-ME supplies. As a result, when ULINK-ME powers the SmartFusion board, some of the board components are not powered and this causes the failure.

RESOLUTION

Prevent ULINK-ME from providing power to the target system. To achieve this remove diode D1 (see picture).

Diode D1 is no longer populated on ULINK-ME Vers.5 or higher.

Last Reviewed: Tuesday, June 28, 2011