If you look in the datasheet for the STM32 (Table 3 on page 20 of the latest datahseet), pins that are 5V tolerant are marked with ''FT'' in the I/O Level column. It is my understanding that these pins can handle up to 5V for an input, but will only be able to generate voltages up to Vdd.
Hope that helps. [ This message was edited by: SJackson on 12-12-2007 14:19 ]