An application note appeared yesterday that should answer your question.
http://cache.freescale.com/files/32bit/doc/app_note/AN4590.pdf?fpsp=1&WT_TYPE=Application Notes&WT_VENDOR=FREESCALE&WT_FILE_FORMAT=pdf&WT_ASSET=Documentation
An application note appeared yesterday that should answer your question.
http://cache.freescale.com/files/32bit/doc/app_note/AN4590.pdf?fpsp=1&WT_TYPE=Application Notes&WT_VENDOR=FREESCALE&WT_FILE_FORMAT=pdf&WT_ASSET=Documentation