硬件平台：STM32F429I-DISCORVERY
软件平台：KEIL MDK5.10
知识点：标准的SDRAM一般都是4个BANK，stm32f429-diso开发板使用的是IS42S16400J这个芯片。
IS42S16400J也有4个Bank，总容量为1Mbitx 16-bit x 4-bank = 67,108,864 bits = 64-Mbit ，每个BANK的组成
4096rows x 256 columns x 16 bits(=16Mbit), 对应的外部引线是12行8列，请参看datasheet.
实验目的：由于TM32F429I-DISCORVERY扩展了sdram，这对于视频播放，图片解码，音频解码，u***大容量数据缓冲
是非常有利的！
实验结果：
1.8Bit 测试成功率为100%，16Bit测试成功率为100%
- #define IS42S16400J_SIZE 0x400000 // 4M x 16Bit(存储宽度)=16Mbit(每个Bank的容量)
-
- int main(void)
- {
- /*!< At this stage the microcontroller clock setting is already configured,
- this is done through SystemInit() function which is called from startup
- files (startup_stm32f429_439xx.s) before to branch to application main.
- To reconfigure the default setting of SystemInit() function, refer to
- system_stm32f4xx.c file
- */
-
- uint8_t ubWritedata_8b = 0x3C, ubReaddata_8b = 0;
- uint16_t uhWritedata_16b = 0x1E5A, uhReaddata_16b = 0;
- uint32_t uwReadwritestatus = 0;
- uint32_t counter = 0x0;
-
- SysTick_Init();
- STM_EVAL_LED_Config();
- STM_EVAL_PBInit(BUTTON_MODE_EXTI);
-
- /* Initialize the LCD */
- LCD_Init();
- LCD_LayerInit();
- LTDC_Cmd(ENABLE);
- LCD_SetLayer(LCD_FOREGROUND_LAYER);
- LCD_Clear(LCD_COLOR_BLUE);
-
- /* Disable write protection */
- FMC_SDRAMWriteProtectionConfig(FMC_Bank2_SDRAM,DISABLE);
-
-
- while (1)
- {
-
- /*********************** 8-bits AHB transaction test ************************/
- /* Wait for User button to be pressed */
- while (STM_EVAL_PBGetState() != Bit_SET)
- {}
- STM_EVAL_LEDOff(LED3);
- STM_EVAL_LEDOff(LED4);
- /* Wait for User button is released */
- while (STM_EVAL_PBGetState() != Bit_RESET)
- {}
-
- /* Erase SDRAM memory */
- for (counter = 0x00; counter < IS42S16400J_SIZE; counter++)
- {
- *(__IO uint8_t*) (SDRAM_BANK_ADDR + counter) = (uint8_t)0x0;
- }
-
- /* Write data value to all SDRAM memory */
- for (counter = 0; counter < IS42S16400J_SIZE; counter++)
- {
- *(__IO uint8_t*) (SDRAM_BANK_ADDR + counter) = (uint8_t)(ubWritedata_8b + counter);
- }
-
- /* Read back SDRAM memory and check content correctness*/
- counter = 0;
- uwReadwritestatus = 0;
- while ((counter < IS42S16400J_SIZE) && (uwReadwritestatus == 0))
- {
- ubReaddata_8b = *(__IO uint8_t*)(SDRAM_BANK_ADDR + counter);
- if ( ubReaddata_8b != (uint8_t)(ubWritedata_8b + counter))
- {
- uwReadwritestatus = 1;
- }
- counter++;
- }
- if(uwReadwritestatus == 0)
- {
- STM_EVAL_LEDOn(LED3);
- STM_EVAL_LEDOff(LED4);
- LCD_Clear(LCD_COLOR_GREEN);
- LCD_DisplayStringLine(LCD_LINE_4, (uint8_t *)" 8-bits AHB ");
- LCD_DisplayStringLine(LCD_LINE_5, (uint8_t *)" Transaction ");
- LCD_DisplayStringLine(LCD_LINE_6, (uint8_t *)" Test-> OK ");
- }
- else
- {
- STM_EVAL_LEDOn(LED4);
- STM_EVAL_LEDOff(LED3);
- LCD_Clear(LCD_COLOR_RED);
- LCD_DisplayStringLine(LCD_LINE_4, (uint8_t *)" 8-bits AHB ");
- LCD_DisplayStringLine(LCD_LINE_5, (uint8_t *)" Transaction ");
- LCD_DisplayStringLine(LCD_LINE_6, (uint8_t *)" Test-> Failed ");
- }
-
- /*********************** 16-bits AHB transaction test ***********************/
- /* Wait for User button to be pressed */
- while (STM_EVAL_PBGetState() != Bit_SET)
- {}
- /* Turn Off Leds */
- STM_EVAL_LEDOff(LED3);
- STM_EVAL_LEDOff(LED4);
-
- /* Wait for User button is released */
- while (STM_EVAL_PBGetState() != Bit_RESET)
- {}
-
-
- /* Erase SDRAM memory */
- for (counter = 0x00; counter < IS42S16400J_SIZE; counter++)
- {
- *(__IO uint16_t*) (SDRAM_BANK_ADDR + 2*counter) = (uint16_t)0x00;
- }
-
- /* Write data value to all SDRAM memory */
- for (counter = 0; counter < IS42S16400J_SIZE; counter++)
- {
- *(__IO uint16_t*) (SDRAM_BANK_ADDR + 2*counter) = (uint16_t)(uhWritedata_16b + counter);
- }
-
- /* Read back SDRAM memory and check content correctness*/
- counter = 0;
- uwReadwritestatus = 0;
- while ((counter < IS42S16400J_SIZE) && (uwReadwritestatus == 0))
- {
- uhReaddata_16b = *(__IO uint16_t*)(SDRAM_BANK_ADDR + 2*counter);
- if ( uhReaddata_16b != (uint16_t)(uhWritedata_16b + counter))
- {
- uwReadwritestatus = 1;
- }
- counter++;
- }
- if(uwReadwritestatus == 0)
- {
- STM_EVAL_LEDOn(LED3);
- STM_EVAL_LEDOff(LED4);
- LCD_Clear(LCD_COLOR_GREEN);
- LCD_DisplayStringLine(LCD_LINE_4, (uint8_t *)" 16-bits AHB ");
- LCD_DisplayStringLine(LCD_LINE_5, (uint8_t *)" Transaction ");
- LCD_DisplayStringLine(LCD_LINE_6, (uint8_t *)" Test-> OK ");
- }
- else
- {
- STM_EVAL_LEDOn(LED4);
- STM_EVAL_LEDOff(LED3);
- LCD_Clear(LCD_COLOR_RED);
- LCD_DisplayStringLine(LCD_LINE_4, (uint8_t *)" 16-bits AHB ");
- LCD_DisplayStringLine(LCD_LINE_5, (uint8_t *)" Transaction ");
- LCD_DisplayStringLine(LCD_LINE_6, (uint8_t *)" Test-> Failed ");
- }
- }
- }
8bit 数据测试：
3
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请问读写SDRAM不需要对应时序图吗？看代码里并没有关于时序或者等待的部分
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/6 
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