Comprehensive Guide to ARM Cortex-M3 GPIO Interface
1、GPIO Structure and Registers
GPIO includes multiple 16-bit I/O ports, each of which can independently set 3 types of input modes and 4 types of output modes, and can be independently set or reset.
GPIO consists of registers, input drivers, output drivers, and other components, as shown in the figure below.
GPIO operates through 7 32-bit registers:
The 4 configuration