stm32 灵活静态存储控制器(FSMC)(NORFLASH\PSRAM)
最后更新于:2022-04-01 14:51:23
Flexible static memory controller(FSMC)
今天在处理TFT彩屏的时候突然发现有人用FSMC控制器来处理,然后就认真的研究了下FSMC;
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可见他分为4个块,三个类型,我们可以根据自己的需要来选择;这次我就直说FSMC 的Block 1;
首先,基地址BASE_ADDR = 6000 0000;至于片选,datasheet上也说了,我们可以通过控制HADDR(27,26)来选择操作;
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然后还有今天一直困扰我的问题,我要选择A16,我用的是16位数据,他的数据地址为6000 0000 + 2^16*2 = 6002 0000;我一直都在疑惑:明明是A16,为什么是第17位被置1,后来终于在datasheet上发现这个问题的根源!
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上面说的很清楚,数据宽度为16位时,HADDR[25:1]与FSMC_A[24:0]相连,那么这时候的FSMC_A16,就与HADDR[17]相连,所以地址就是6000 0000 + 2^17;
下面来看看FSMC如何与TFT联系起来!
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A16 --> RS -- 使能
D0~D15 数据线
FSMC_WE --> WE
FSMC_OE --> OE
这个连接方式让我想起了微机原理上的8059;呵呵,如果你学过了微机原理,看到这个图应该懂了80%;
代码分析:
~~~
FSMC_NORSRAMInitTypeDef FSMC_NORSRAMInitStructure;
FSMC_NORSRAMTimingInitTypeDef p;
GPIO_InitTypeDef GPIO_InitStructure;
RCC_AHBPeriphClockCmd(RCC_AHBPeriph_FSMC, ENABLE);
RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOA | RCC_APB2Periph_GPIOB | RCC_APB2Periph_GPIOC |
RCC_APB2Periph_GPIOD | RCC_APB2Periph_GPIOE , ENABLE);
GPIO_InitStructure.GPIO_Pin = GPIO_Pin_13;
GPIO_InitStructure.GPIO_Mode = GPIO_Mode_Out_PP;
GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;
GPIO_Init(GPIOD, &GPIO_InitStructure);
GPIO_SetBits(GPIOD, GPIO_Pin_13);
GPIO_InitStructure.GPIO_Pin = GPIO_Pin_1;
GPIO_InitStructure.GPIO_Mode = GPIO_Mode_Out_PP;
GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;
GPIO_Init(GPIOE, &GPIO_InitStructure);
GPIO_InitStructure.GPIO_Pin = GPIO_Pin_0 | GPIO_Pin_1 | GPIO_Pin_4 | GPIO_Pin_5 |
GPIO_Pin_8 | GPIO_Pin_9 | GPIO_Pin_10 | GPIO_Pin_14 |
GPIO_Pin_15;
GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;
GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF_PP;
GPIO_Init(GPIOD, &GPIO_InitStructure);
GPIO_InitStructure.GPIO_Pin = GPIO_Pin_7 | GPIO_Pin_8 | GPIO_Pin_9 | GPIO_Pin_10 |
GPIO_Pin_11 | GPIO_Pin_12 | GPIO_Pin_13 | GPIO_Pin_14 |
GPIO_Pin_15;
GPIO_Init(GPIOE, &GPIO_InitStructure);
GPIO_InitStructure.GPIO_Pin = GPIO_Pin_7;
GPIO_Init(GPIOD, &GPIO_InitStructure);
GPIO_InitStructure.GPIO_Pin = GPIO_Pin_11 ;
GPIO_Init(GPIOD, &GPIO_InitStructure);
p.FSMC_AddressSetupTime = 0x02;
p.FSMC_AddressHoldTime = 0x02;
p.FSMC_DataSetupTime = 0x05;
p.FSMC_AccessMode = FSMC_AccessMode_B;
FSMC_NORSRAMInitStructure.FSMC_Bank = FSMC_Bank1_NORSRAM1;
FSMC_NORSRAMInitStructure.FSMC_DataAddressMux = FSMC_DataAddressMux_Disable;
FSMC_NORSRAMInitStructure.FSMC_MemoryType = FSMC_MemoryType_NOR;
FSMC_NORSRAMInitStructure.FSMC_MemoryDataWidth = FSMC_MemoryDataWidth_16b;
FSMC_NORSRAMInitStructure.FSMC_BurstAccessMode = FSMC_BurstAccessMode_Disable;
FSMC_NORSRAMInitStructure.FSMC_WaitSignalPolarity = FSMC_WaitSignalPolarity_Low;
FSMC_NORSRAMInitStructure.FSMC_WrapMode = FSMC_WrapMode_Disable;
FSMC_NORSRAMInitStructure.FSMC_WaitSignalActive = FSMC_WaitSignalActive_BeforeWaitState;
FSMC_NORSRAMInitStructure.FSMC_WriteOperation = FSMC_WriteOperation_Enable;
FSMC_NORSRAMInitStructure.FSMC_WaitSignal = FSMC_WaitSignal_Disable;
FSMC_NORSRAMInitStructure.FSMC_ExtendedMode = FSMC_ExtendedMode_Disable;
FSMC_NORSRAMInitStructure.FSMC_WriteBurst = FSMC_WriteBurst_Disable;
FSMC_NORSRAMInitStructure.FSMC_ReadWriteTimingStruct = &p;
FSMC_NORSRAMInitStructure.FSMC_WriteTimingStruct = &p;
FSMC_NORSRAMInit(&FSMC_NORSRAMInitStructure);
FSMC_NORSRAMCmd(FSMC_Bank1_NORSRAM1, ENABLE);
~~~
时钟初始化是必须的!希望大家不要forget了!
另外gpio的初始化,要看两个地方:1,数据手册上,每种管脚初始化成什么模式;2,哪些管脚需要初始化;
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管脚对应自己对着原理图一个一个找!
FSMC_NORSRAMTimingInitTypeDef 设置
p.FSMC_AddressSetupTime = 0x02;
p.FSMC_AddressHoldTime = 0x02;
p.FSMC_DataSetupTime = 0x05;
p.FSMC_AccessMode = FSMC_AccessMode_B;
这里我只设置了4项,因为其他几项都是与norflash有关的,所以我们不用设置,因为TFT内部是RAM;
具体时间参考,在datasheet上也给了说明:
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见网上有人设置FSMC_ADDressHoldTime = 0x0;发现也没啥影响,但是我们还是最好按照这个标准来!因为毕竟是官方给的标准!
~~~
FSMC_NORSRAMInitStructure.FSMC_Bank = FSMC_Bank1_NORSRAM1;
~~~
选择Bank1_NORSRAM1;因为我们本身就是选的他毋庸置疑;
~~~
FSMC_NORSRAMInitStructure.FSMC_DataAddressMux = FSMC_DataAddressMux_Disable;
~~~
我再TFT上也没有用到多路复用,因为我就只是跟TFT通信,说到这,我们还可以用它来控制4个彩屏一起显示!
~~~
FSMC_NORSRAMInitStructure.FSMC_MemoryType = FSMC_MemoryType_PSRAM;
~~~
这个参数是用来选择到底是哪个类型的存储器,他有三个option:
~~~
#define FSMC_MemoryType_SRAM ((uint32_t)0x00000000)
#define FSMC_MemoryType_PSRAM ((uint32_t)0x00000004)
#define FSMC_MemoryType_NOR ((uint32_t)0x00000008)
~~~
因为我不知道彩屏的内存到底是哪种类型的,我测试了下,三个选项对彩屏都是一样的效果,因为我对SRAM,NOR比较熟悉,所以就选了一个不熟悉的选项;
~~~
FSMC_NORSRAMInitStructure.FSMC_MemoryDataWidth = FSMC_MemoryDataWidth_16b;
~~~
16位的数据宽度
~~~
FSMC_NORSRAMInitStructure.FSMC_BurstAccessMode = FSMC_BurstAccessMode_Disable;
FSMC_NORSRAMInitStructure.FSMC_WaitSignalPolarity = FSMC_WaitSignalPolarity_Low;
FSMC_NORSRAMInitStructure.FSMC_WrapMode = FSMC_WrapMode_Disable;
FSMC_NORSRAMInitStructure.FSMC_WaitSignalActive = FSMC_WaitSignalActive_BeforeWaitState;
FSMC_NORSRAMInitStructure.FSMC_WriteOperation = FSMC_WriteOperation_Enable;
FSMC_NORSRAMInitStructure.FSMC_WaitSignal = FSMC_WaitSignal_Disable;
FSMC_NORSRAMInitStructure.FSMC_ExtendedMode = FSMC_ExtendedMode_Disable;
FSMC_NORSRAMInitStructure.FSMC_WriteBurst = FSMC_WriteBurst_Disable;
FSMC_NORSRAMInitStructure.FSMC_ReadWriteTimingStruct = &p;
FSMC_NORSRAMInitStructure.FSMC_WriteTimingStruct = &p;
~~~
然后我的彩屏控制基地址为
~~~
#define Bank1_LCD_DATA ((uint32_t)0x60020000)
#define Bank1_LCD_CTL ((uint32_t)0x60000000)
~~~
使用方法:
~~~
*(__IO uint16_t *) (Bank1_LCD_C)= reg;
*(__IO uint16_t *) (Bank1_LCD_D)= cmd;
~~~
可能理解的还不是太好,请大家多多指点;