rt-thread-official/bsp/swm320/libraries/SWM320_StdPeriph_Driver/SWM320_sram.c

/****************************************************************************************************************************************** 
* 文件名称: SWM320_sram.c
* 功能说明:	SWM320单片机的SRAM驱动程序
* 技术支持:	http://www.synwit.com.cn/e/tool/gbook/?bid=1
* 注意事项:
* 版本日期: V1.1.0		2017年10月25日
* 升级记录: 
*
*
*******************************************************************************************************************************************
* @attention
*
* THE PRESENT FIRMWARE WHICH IS FOR GUIDANCE ONLY AIMS AT PROVIDING CUSTOMERS WITH CODING INFORMATION 
* REGARDING THEIR PRODUCTS IN ORDER FOR THEM TO SAVE TIME. AS A RESULT, SYNWIT SHALL NOT BE HELD LIABLE 
* FOR ANY DIRECT, INDIRECT OR CONSEQUENTIAL DAMAGES WITH RESPECT TO ANY CLAIMS ARISING FROM THE CONTENT 
* OF SUCH FIRMWARE AND/OR THE USE MADE BY CUSTOMERS OF THE CODING INFORMATION CONTAINED HEREIN IN CONN-
* -ECTION WITH THEIR PRODUCTS.
*
* COPYRIGHT 2012 Synwit Technology 
*******************************************************************************************************************************************/
#include "SWM320.h"
#include "SWM320_sram.h"

/****************************************************************************************************************************************** 
* 函数名称:	SRAM_Init()
* 功能说明:	SRAM控制器初始化
* 输    入: SRAM_InitStructure * initStruct    包含 SRAM 控制器相关设定值的结构体
* 输    出: 无
* 注意事项: 无
******************************************************************************************************************************************/
void SRAM_Init(SRAM_InitStructure *initStruct)
{
    uint32_t i;

    // 配置SRAM前需要刷新下SDRAM控制器
    do
    {
        SYS->CLKEN |= (1 << SYS_CLKEN_SDRAM_Pos);

        while (SDRAMC->REFDONE == 0)
            ;
        SDRAMC->REFRESH &= ~(1 << SDRAMC_REFRESH_EN_Pos);

        for (i = 0; i < 1000; i++)
            __NOP();
        SYS->CLKEN &= ~(1 << SYS_CLKEN_SDRAM_Pos);
    } while (0);

    SYS->CLKEN |= (1 << SYS_CLKEN_RAMC_Pos);
    for (i = 0; i < 10; i++)
        __NOP();

    SRAMC->CR = (initStruct->ClkDiv << SRAMC_CR_RWTIME_Pos) |
                (initStruct->DataWidth << SRAMC_CR_BYTEIF_Pos) |
                (0 << SRAMC_CR_HBLBDIS_Pos); // 使能字节、半字访问
}