Stm32f10x -- C Language-1

review 51 Single chip microcomputer :

Register mapping ： The memory corresponding to each peripheral has an address , By keyword （ for example sfr） Implement register mapping , Name the address .

MCU has port （51 Yes 4 individual ）, The corresponding address 0x80,0x90,0xA0,0xB0, adopt

sfr P0 = 0x80; 
sfr P1 = 0x90;
sfr P2 = 0xA0;
sfr P3 = 0xB0;

  Implement register definition . Use directly when programming P0 Assign a value , Such as ：

P0 = 0xFE; /*51 Only 8 bits,0b11111110*/

STM32F103：

Let someone GPIO Port of 16 Pin implementation high / Low level output （ meanwhile ）：

（ port ） Output data register ODR（output data register）, low 16 Bit effective ,16 All pins output low level, so it is necessary to turn low 16 The bits are set to 1 that will do .

The connection indicator of your board is GPIOE, stay “ Bus architecture ” Port found E Address range : 0x40011800-0x40010FFE.

Address offset ： The offset of the register from the bus base address , Here is 0x4001180C.

(unsigned int *) The role of :  Cast

GPIOE_ODR The address is 0x4001180C, The compiler does not consider it an address , So we need to use

(unsigned int *)0x4001180C;

Yes 0x4001180C Cast .

“*” The role of ： Pointer the address . namely ：

*(unsigned int*)0x4001180C; 

The above is the most basic and cumbersome implementation , You can optimize with macro definitions . The box #define Address (unsigned int *)0x4001180C Defined as a macro , sentence ：

#define GPIOE_ODR (unsigned int*)0x4001180C; 

  Then operate the macro with pointer and assign value , sentence ：

* GPIOE_ODR = 0xFF;

You can put the previous sentence * Move the number to the macro definition statement , namely ：

#define GPIOE_ODR *(unsigned int*)0x4001180C; 

Direct assignment ：

GPIOE_ODR = 0xFF;