We made a board with LPC54608J512 BD208. We planned to use USB1 for flashing user code. We also have a 12MHz crystal on board. We also have a ISP-connector as secondary means to flash applications but rather not use it for production. So far the board does what it should, but we can't get USB1 working from bootloader.
When pulling down ISP2 the boot-ROM tries to initiate USB-connection. However the device isn't correctly registered as MSC by Windows, it just says "unknown device".
When we pull down ISP1 and ISP2 it's the same, it doesn't register as "LPC" as the demo boards (OM13092 and OM13098) do.
We have no idea how to debug or proceed.
It seems guanix asked the same question in another thread Crystal value for LPC546xx USB ISP bootloader
Is this a known problem? Any hints on how to find out what's going wrong?