I have looked through two datasheets and user manuals now for two different microcontrollers (LPC2387 and STM32F4xx), and I haven't found (probably missed) anywhere where the initial state of the GPIO pins was described on powerup or after reset.
My question is not specific for these MCUs, but in general, is it most common for GPIO pins to be initialized as input-floating (high-z) upon reset? Is there a standard convention, or do different MCUs do different things, and one needs to read the datasheet/manual for each MCU one works with?