软件模拟I2C时输入与输出切换

一 为达到类似C51的操作需要添加以下位带操作：#include "stm32f10x_gpio.h"
#include "stm32f10x_conf.h"

/* IO地址映射*/
#define GPIOA_ODR_Addr    (GPIOA_BASE+12) //0x4001080C
#define GPIOB_ODR_Addr    (GPIOB_BASE+12) //0x40010C0C
#define GPIOC_ODR_Addr    (GPIOC_BASE+12) //0x4001100C
#define GPIOD_ODR_Addr    (GPIOD_BASE+12) //0x4001140C
#define GPIOE_ODR_Addr    (GPIOE_BASE+12) //0x4001180C
#define GPIOF_ODR_Addr    (GPIOF_BASE+12) //0x40011A0C    
#define GPIOG_ODR_Addr    (GPIOG_BASE+12) //0x40011E0C

#define GPIOA_IDR_Addr    (GPIOA_BASE+8) //0x40010808
#define GPIOB_IDR_Addr    (GPIOB_BASE+8) //0x40010C08
#define GPIOC_IDR_Addr    (GPIOC_BASE+8) //0x40011008
#define GPIOD_IDR_Addr    (GPIOD_BASE+8) //0x40011408
#define GPIOE_IDR_Addr    (GPIOE_BASE+8) //0x40011808
#define GPIOF_IDR_Addr    (GPIOF_BASE+8) //0x40011A08
#define GPIOG_IDR_Addr    (GPIOG_BASE+8) //0x40011E08

/* 输入 */
#define PAin(n)        *((volatile unsigned long *)(0x42000000+((GPIOA_IDR_Addr-0x40000000)<<5)+(n<<2)))
#define PBin(n)        *((volatile unsigned long *)(0x42000000+((GPIOB_IDR_Addr-0x40000000)<<5)+(n<<2)))
#define PCin(n)        *((volatile unsigned long *)(0x42000000+((GPIOC_IDR_Addr-0x40000000)<<5)+(n<<2)))
#define PDin(n)        *((volatile unsigned long *)(0x42000000+((GPIOD_IDR_Addr-0x40000000)<<5)+(n<<2)))
#define PEin(n)        *((volatile unsigned long *)(0x42000000+((GPIOE_IDR_Addr-0x40000000)<<5)+(n<<2)))
#define PFin(n)        *((volatile unsigned long *)(0x42000000+((GPIOF_IDR_Addr-0x40000000)<<5)+(n<<2)))

/* 输出 */
#define PAout(n)    *((volatile unsigned long *)(0x42000000+((GPIOA_ODR_Addr-0x40000000)<<5)+(n<<2)))
#define PBout(n)    *((volatile unsigned long *)(0x42000000+((GPIOB_ODR_Addr-0x40000000)<<5)+(n<<2)))
#define PCout(n)    *((volatile unsigned long *)(0x42000000+((GPIOC_ODR_Addr-0x40000000)<<5)+(n<<2)))
#define PDout(n)    *((volatile unsigned long *)(0x42000000+((GPIOD_ODR_Addr-0x40000000)<<5)+(n<<2)))
#define PEout(n)    *((volatile unsigned long *)(0x42000000+((GPIOE_ODR_Addr-0x40000000)<<5)+(n<<2)))

二 假设SDA=PB0,SCL=PB1:

#define SDA_IN()  {GPIOB->CRL&=0XFFFFFFF0;GPIOB->CRL|=8<<0;} /*也就是对应的GPIO输入输出配置寄存器进行操作：PB0的输入上拉*/
#define SDA_OUT() {GPIOB->CRL&=0XFFFFFFF0;GPIOB->CRL|=3<<0;}/*PB0的上拉，输出速度50MHZ*/
#define IIC_SCL    PBout(1) /*相当于操作函数GPIO_WriteBit*/
#define IIC_SDA    PBout(0)         
#define READ_SDA   PBin(0)  /*相当于操作函数GPIO_ReadInputDataBit*/