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#include <stdio.h>
#include <stm32f10x.h>
#define _BV(n) (1u << (n))
uint16_t rca;
// 延时n毫秒
void delay(uint16_t n)
{
TIM6->ARR = 10 * n - 1; // nms
TIM6->PSC = 7199; // 72MHz/7200=10kHz
TIM6->CR1 = TIM_CR1_URS | TIM_CR1_OPM; // UG不置位UIF, 非循环模式
TIM6->EGR = TIM_EGR_UG; // 保存设置
TIM6->CR1 |= TIM_CR1_CEN; // 开始计时
while ((TIM6->SR & TIM_SR_UIF) == 0); // 等待计时完毕
TIM6->SR &= ~TIM_SR_UIF; // 清除溢出标志
}
int fputc(int ch, FILE *fp)
{
if (fp == stdout)
{
if (ch == '\n')
{
while ((USART1->SR & USART_SR_TXE) == 0);
USART1->DR = '\r';
}
while ((USART1->SR & USART_SR_TXE) == 0);
USART1->DR = ch;
}
return ch;
}
// 检查命令是否收到了回应, 若没收到则重发命令
void Card_CheckCommand(void)
{
while (SDIO->STA & SDIO_STA_CTIMEOUT)
{
SDIO->ICR = SDIO_ICR_CTIMEOUTC; // 清除标志
SDIO->CMD = SDIO->CMD; // 重发
printf("Timeout! Resend CMD%d\n", SDIO->CMD & SDIO_CMD_CMDINDEX);
while (SDIO->STA & SDIO_STA_CMDACT);
}
}
void Card_SendCMD52(uint8_t is_write, uint8_t read_after_write, uint8_t function_number, uint32_t register_address, uint8_t data_to_write)
{
SDIO->ARG = (is_write << 31) | (function_number << 28) | (read_after_write << 27) | (register_address << 9) | data_to_write;
SDIO->CMD = SDIO_CMD_CPSMEN | SDIO_CMD_WAITRESP_0 | 52;
while (SDIO->STA & SDIO_STA_CMDACT);
}
void Card_ShowShortResponse(void)
{
printf("Command response received: CMD%d, RESP_%08x\n", SDIO->RESPCMD, SDIO->RESP1);
}
// 读寄存器
uint8_t Card_Read(uint8_t func_num, uint32_t addr)
{
Card_SendCMD52(0, 0, func_num, addr, 0);
if (SDIO->STA & SDIO_STA_CMDREND)
{
SDIO->ICR = SDIO_ICR_CMDRENDC;
return SDIO->RESP1 & 0xff;
}
else
{
printf("Card_Read failed, SDIO->STA=0x%08x!\n", SDIO->STA);
return 0;
}
}
// 写寄存器, 返回写入后寄存器的实际内容
uint8_t Card_Write(uint8_t func_num, uint32_t addr, uint8_t value)
{
Card_SendCMD52(1, 1, func_num, addr, value);
if (SDIO->STA & SDIO_STA_CMDREND)
{
SDIO->ICR = SDIO_ICR_CMDRENDC;
return SDIO->RESP1 & 0xff;
}
else
{
printf("Card_Write failed, SDIO->STA=0x%08x!\n", SDIO->STA);
return 0;
}
}
// SDIO Simplified Specification Version 3.00
// 3. SDIO Card Initialization
void Card_Init(void)
{
printf("Initialization begins...\n");
SDIO->POWER = SDIO_POWER_PWRCTRL;
SDIO->CLKCR = SDIO_CLKCR_CLKEN | 178; // 初始化时最高允许的频率: 72MHz/(178+2)=400kHz
delay(5); // 延时可防止CMD5重发
// 不需要发送CMD0, 因为SD I/O card的初始化命令是CMD52
// An I/O only card or the I/O portion of a combo card is NOT reset by CMD0. (See 4.4 Reset for SDIO)
/* 发送CMD5: IO_SEND_OP_COND */
SDIO->CMD = SDIO_CMD_CPSMEN | SDIO_CMD_WAITRESP_0 | 5;
while (SDIO->STA & SDIO_STA_CMDACT);
Card_CheckCommand(); // 为了保险起见还是要检查一下是否要重发命令
if (SDIO->STA & SDIO_STA_CMDREND)
{
SDIO->ICR = SDIO_ICR_CMDRENDC;
Card_ShowShortResponse();
}
/* 设置参数VDD Voltage Window: 3.2~3.4V, 并再次发送CMD5 */
SDIO->ARG = 0x300000;
SDIO->CMD = SDIO->CMD;
while (SDIO->STA & SDIO_STA_CMDACT);
if (SDIO->STA & SDIO_STA_CMDREND)
{
SDIO->ICR = SDIO_ICR_CMDRENDC;
Card_ShowShortResponse();
if (SDIO->RESP1 & _BV(31))
{
// Card is ready to operate after initialization
printf("Number of I/O Functions: %d\n", (SDIO->RESP1 >> 28) & 7);
printf("Memory Present: %d\n", (SDIO->RESP1 & _BV(27)) != 0);
}
}
/* 获取Wi-Fi模块地址 (CMD3: SEND_RELATIVE_ADDR, Ask the card to publish a new relative address (RCA)) */
SDIO->ARG = 0;
SDIO->CMD = SDIO_CMD_CPSMEN | SDIO_CMD_WAITRESP_0 | 3;
while (SDIO->STA & SDIO_STA_CMDACT);
if (SDIO->STA & SDIO_STA_CMDREND)
{
SDIO->ICR = SDIO_ICR_CMDRENDC;
rca = SDIO->RESP1 >> 16;
printf("Relative card address: 0x%04x\n", rca);
}
/* 选中Wi-Fi模块 (CMD7: SELECT/DESELECT_CARD) */
SDIO->ARG = rca << 16;
SDIO->CMD = SDIO_CMD_CPSMEN | SDIO_CMD_WAITRESP_0 | 7;
while (SDIO->STA & SDIO_STA_CMDACT);
if (SDIO->STA & SDIO_STA_CMDREND)
{
SDIO->ICR = SDIO_ICR_CMDRENDC;
printf("Card selected! status=0x%08x\n", SDIO->RESP1);
}
// 提高时钟频率
SDIO->CLKCR = (SDIO->CLKCR & ~SDIO_CLKCR_CLKDIV) | 70; // 72MHz/(70+2)=1MHz
SDIO->DTIMER = 1000000; // 当频率为1MHz时, 超时时间为1秒
//SDIO->CLKCR = (SDIO->CLKCR & ~SDIO_CLKCR_CLKDIV) | 1; // 72MHz/(1+2)=24MHz
/* 选择总线宽度 (Wide Bus Selection) */
// For an SDIO card a write to the CCCR using CMD52 is used to select bus width. (See 4.5 Bus Width)
// CMD52: IO_RW_DIRECT, CCCR: Card Common Control Registers
Card_Write(0, 0x07, Card_Read(0, 0x07) | 0x02); // Bus Width: 4-bit bus
SDIO->CLKCR |= SDIO_CLKCR_WIDBUS_0;
}
int main(void)
{
RCC->AHBENR = RCC_AHBENR_SDIOEN;
RCC->APB1ENR = RCC_APB1ENR_TIM6EN;
RCC->APB2ENR = RCC_APB2ENR_IOPAEN | RCC_APB2ENR_IOPBEN | RCC_APB2ENR_IOPCEN | RCC_APB2ENR_IOPDEN| RCC_APB2ENR_USART1EN;
GPIOA->CRH = 0x000004b0;
GPIOB->CRH = 0x00030000; // PB12为WiFi模块电源开关, PB12=0时打开WiFi模块
GPIOC->CRH = 0x000bbbbb;
GPIOD->CRL = 0x00000b00;
USART1->BRR = 0x271;
USART1->CR1 = USART_CR1_UE | USART_CR1_TE;
Card_Init();
while (1);
}
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