One of the more common things you do as an Embedded Systems programmer is accessing registers of different peripherals.

Rather than hardcoding the address to each and every register in a peripheral, I find it convenient to typedef a C-struct for easy access of these registers. Setup the struct with a layout identical to that of your hardware registers, assign a pointer to the structure to point at the (base)address of the hardware registers in question, and voila! Access each register as a regular element of the structure for read/write operations.

typedef struct {
volatile uint8_t STATUS;
volatile uint8_t TX_REG;
volatile uint8_t RX_REG;
} hw_device_t;

hw_device->RX_REG = 0x10;
hw_device->TX_REF = 0x03;
uint8_t current_status = hw_device->STATUS;

Note: all elements of structure should be made volatile to avoid compiler optimizations.