Hi @ all, I've designed a PCB with a SAF-XE164FM-72F80L ES-AA. Environmental Setup: Controller is connected on my PCB, as recommended in AP16146 V1.0 2009-09 08 Single Power Supply 5VDC. The Startup Mode is as described in Chapter 2.4 Table 2 (JTAG pos.B) VDDIM and VDDI1 (Core Supply, which the controller generate internally) are 1.5V. My problem is, Infineon Memtool 4.2 can't establish Connection to Target. What I already did is, I checked the Crystal with the Scope -> there was no frequency measurable. When I placed this Crystal in another PCB, its working without any problems. I have also a PCB with the same environmental setup but with a SAF-XE167FM-72F80L ES-AA. This configuration is working without any problems. For me it seems like the Controller is in the "Stopover Mode" described in Chapter 4.2.3 (Datasheet V2.0 2009-03), but I don't know why and how I have to "wake it up". Thanks a lot in advance for your support.