92 lines
4.0 KiB
C
92 lines
4.0 KiB
C
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/******************************************************************************************************************************************
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* 文件名称: SWM341_sdram.c
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* 功能说明: SWM341单片机的SDRAM驱动程序
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* 技术支持: http://www.synwit.com.cn/e/tool/gbook/?bid=1
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* 注意事项:
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* 版本日期: V1.1.0 2017年10月25日
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* 升级记录:
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*
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*
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*******************************************************************************************************************************************
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* @attention
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*
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* THE PRESENT FIRMWARE WHICH IS FOR GUIDANCE ONLY AIMS AT PROVIDING CUSTOMERS WITH CODING INFORMATION
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* REGARDING THEIR PRODUCTS IN ORDER FOR THEM TO SAVE TIME. AS A RESULT, SYNWIT SHALL NOT BE HELD LIABLE
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* FOR ANY DIRECT, INDIRECT OR CONSEQUENTIAL DAMAGES WITH RESPECT TO ANY CLAIMS ARISING FROM THE CONTENT
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* OF SUCH FIRMWARE AND/OR THE USE MADE BY CUSTOMERS OF THE CODING INFORMATION CONTAINED HEREIN IN CONN-
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* -ECTION WITH THEIR PRODUCTS.
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*
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* COPYRIGHT 2012 Synwit Technology
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*******************************************************************************************************************************************/
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#include "SWM341.h"
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#include "SWM341_sdram.h"
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/******************************************************************************************************************************************
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* 函数名称: SDRAM_Init()
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* 功能说明: SDRAM控制器初始化
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* 输 入: SDRAM_InitStructure * initStruct 包含 SDRAM 控制器相关设定值的结构体
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* 输 出: 无
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* 注意事项: 无
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******************************************************************************************************************************************/
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void SDRAM_Init(SDRAM_InitStructure * initStruct)
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{
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uint32_t cyclesPerUs = CyclesPerUs / (initStruct->ClkDiv + 1); // 1us有多少个SDRAM_CLK周期
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uint32_t row_n;
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SYS->CLKEN1 |= (1 << SYS_CLKEN1_SDRAM_Pos);
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SDRAMC->TIM = (initStruct->TimeTRP << SDRAMC_TIM_TRP_Pos) |
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(initStruct->TimeTRCD << SDRAMC_TIM_TRCD_Pos) |
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(initStruct->TimeTRFC << SDRAMC_TIM_TRFC_Pos) |
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((cyclesPerUs * 200) << SDRAMC_TIM_T100US_Pos); // 要求大于100us
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SDRAMC->CFG = (initStruct->Size << SDRAMC_CFG_SIZE_Pos) |
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(initStruct->ClkDiv << SDRAMC_CFG_CLKDIV_Pos) |
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(initStruct->CASLatency << SDRAMC_CFG_CASDELAY_Pos) |
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(((SystemCoreClock / (initStruct->ClkDiv + 1)) > 66000000) << SDRAMC_CFG_HIGHFREQ_Pos);
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switch(initStruct->Size)
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{
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case SDRAM_SIZE_2MB: row_n = 2048; break;
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case SDRAM_SIZE_8MB: row_n = 4096; break;
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case SDRAM_SIZE_16MB: row_n = 4096; break;
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case SDRAM_SIZE_32MB: row_n = 8192; break;
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default: row_n = 4096; break;
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}
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SDRAMC->T64 = (64*1000 / row_n + 1) * cyclesPerUs;
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SDRAMC->CR = (1 << SDRAMC_CR_PWRON_Pos);
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while(SDRAMC->CR & SDRAMC_CR_PWRON_Msk) __NOP(); //等待初始完成
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}
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/******************************************************************************************************************************************
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* 函数名称: SDRAM_Enable()
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* 功能说明: SDRAM使能，使能后可读写SDRAM
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* 输 入: 无
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* 输 出: 无
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* 注意事项: 无
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******************************************************************************************************************************************/
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void SDRAM_Enable(void)
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{
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SDRAMC->CR &= ~SDRAMC_CR_ENTERSRF_Msk;
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for(int i = 0; i < 100; i++) __NOP();
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}
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/******************************************************************************************************************************************
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* 函数名称: SDRAM_Disable()
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* 功能说明: SDRAM禁能，禁能后SDRAM颗粒进入低功耗模式、并自刷新，不可读写
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* 输 入: 无
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* 输 出: 无
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* 注意事项: 无
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******************************************************************************************************************************************/
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void SDRAM_Disable(void)
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{
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SDRAMC->CR |= SDRAMC_CR_ENTERSRF_Msk;
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for(int i = 0; i < 100; i++) __NOP();
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}
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