FSMC的RS（A20）无波形

Billuncle 提问时间：2014-11-18 21:21 /

用STM32F103驱动一块3.5寸屏，设置成FSMC模式，但发现SSD1963没有被驱动成功，通过测试波形发现RS（A20）恒为高电压不会变化，但RW、CS则有信号输出，硬件确认此脚接到PE4上，请问是什么原因：
下面是FSMC设置和发送指令和数据的代码

#define LCD_COMM_ADD *((u16 *)0x60000000)
#define LCD_DATA_ADD *((u16 *)0x60200000)
#define LCD_Write16BitIndex(cmd) {LCD_COMM_ADD = cmd;}
#define LCD_Write16BitData(data) {LCD_DATA_ADD = data;}

//FSMC 设置
FSMC_NORSRAMInitTypeDef  FSMC_NORSRAMInitStructure;
FSMC_NORSRAMTimingInitTypeDef p;

  p.FSMC_AddressSetupTime = 2;
  p.FSMC_AddressHoldTime = 0;
  p.FSMC_DataSetupTime = 5;
  p.FSMC_BusTurnAroundDuration = 0;
  p.FSMC_CLKDivision = 0;
  p.FSMC_DataLatency = 0;
  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);

  //* Enable FSMC Bank1_SRAM Bank */
  FSMC_NORSRAMCmd(FSMC_Bank1_NORSRAM1, ENABLE);