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Peter Lissenburg
Associate III
April 17, 2013
Question

FSMC driving LCD 8bit bus, but sending 2 bytes

  • April 17, 2013
  • 2 replies
  • 589 views
Posted on April 17, 2013 at 08:26

Hi all,

I have a ST7753S 8 bit bus, 8080 style, hooked up to STM32F103VE FSMC with config as below. However I find that there are 2 bytes being written every time I write a char. Is this how it works, or am I doing sometimne wrong? Thanks for any assistance. Cheers. Pete L. static void LCD_FSMCConfig(void) { FSMC_NORSRAMInitTypeDef FSMC_NORSRAMInitStructure; FSMC_NORSRAMTimingInitTypeDef FSMC_NORSRAMTimingInitStructure; /* FSMC init*/ FSMC_NORSRAMInitStructure.FSMC_Bank = FSMC_Bank1_NORSRAM1; FSMC_NORSRAMInitStructure.FSMC_DataAddressMux = FSMC_DataAddressMux_Disable; FSMC_NORSRAMInitStructure.FSMC_MemoryType = FSMC_MemoryType_SRAM; FSMC_NORSRAMInitStructure.FSMC_MemoryDataWidth = FSMC_MemoryDataWidth_8b; 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;

static void LCD_FSMCConfig(void)
{
FSMC_NORSRAMInitTypeDef FSMC_NORSRAMInitStructure;
FSMC_NORSRAMTimingInitTypeDef FSMC_NORSRAMTimingInitStructure;
/* FSMC init*/
FSMC_NORSRAMInitStructure.FSMC_Bank = FSMC_Bank1_NORSRAM1; 
FSMC_NORSRAMInitStructure.FSMC_DataAddressMux = FSMC_DataAddressMux_Disable;
FSMC_NORSRAMInitStructure.FSMC_MemoryType = FSMC_MemoryType_SRAM;
FSMC_NORSRAMInitStructure.FSMC_MemoryDataWidth = FSMC_MemoryDataWidth_8b;
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_AsynchronousWait = FSMC_AsynchronousWait_Disable;
FSMC_NORSRAMInitStructure.FSMC_ExtendedMode = FSMC_ExtendedMode_Disable;
FSMC_NORSRAMInitStructure.FSMC_WriteBurst = FSMC_WriteBurst_Disable;
/* FSMC ReadWrite Timing */
FSMC_NORSRAMTimingInitStructure.FSMC_AddressSetupTime = 15;
FSMC_NORSRAMTimingInitStructure.FSMC_AddressHoldTime = 15;
FSMC_NORSRAMTimingInitStructure.FSMC_DataSetupTime = 15;
FSMC_NORSRAMTimingInitStructure.FSMC_BusTurnAroundDuration = 15;
FSMC_NORSRAMTimingInitStructure.FSMC_CLKDivision = 0x00;
FSMC_NORSRAMTimingInitStructure.FSMC_DataLatency = 0x00;
FSMC_NORSRAMTimingInitStructure.FSMC_AccessMode = FSMC_AccessMode_A;
FSMC_NORSRAMInitStructure.FSMC_ReadWriteTimingStruct = &FSMC_NORSRAMTimingInitStructure;
/* FSMC Write Timing */
FSMC_NORSRAMInitStructure.FSMC_WriteTimingStruct = &FSMC_NORSRAMTimingInitStructure;
FSMC_NORSRAMInit(&FSMC_NORSRAMInitStructure);
/* Enable FSMC Bank4_SRAM Bank */
FSMC_NORSRAMCmd(FSMC_Bank1_NORSRAM1, ENABLE);
}

FSMC_NORSRAMInitStructure.FSMC_WaitSignal = FSMC_WaitSignal_Disable; FSMC_NORSRAMInitStructure.FSMC_AsynchronousWait = FSMC_AsynchronousWait_Disable; FSMC_NORSRAMInitStructure.FSMC_ExtendedMode = FSMC_ExtendedMode_Disable; FSMC_NORSRAMInitStructure.FSMC_WriteBurst = FSMC_WriteBurst_Disable; /* FSMC ReadWrite Timing */ FSMC_NORSRAMTimingInitStructure.FSMC_AddressSetupTime = 15; FSMC_NORSRAMTimingInitStructure.FSMC_AddressHoldTime = 15; FSMC_NORSRAMTimingInitStructure.FSMC_DataSetupTime = 15; FSMC_NORSRAMTimingInitStructure.FSMC_BusTurnAroundDuration = 15; FSMC_NORSRAMTimingInitStructure.FSMC_CLKDivision = 0x00; FSMC_NORSRAMTimingInitStructure.FSMC_DataLatency = 0x00; FSMC_NORSRAMTimingInitStructure.FSMC_AccessMode = FSMC_AccessMode_A; FSMC_NORSRAMTimingInitStructure.FSMC_AccessMode = FSMC_AccessMode_A; FSMC_NORSRAMInitStructure.FSMC_ReadWriteTimingStruct = &FSMC_NORSRAMTimingInitStructure; /* FSMC Write Timing */ FSMC_NORSRAMInitStructure.FSMC_WriteTimingStruct = &FSMC_NORSRAMTimingInitStructure; FSMC_NORSRAMInit(&FSMC_NORSRAMInitStructure); /* Enable FSMC Bank4_SRAM Bank */ FSMC_NORSRAMCmd(FSMC_Bank1_NORSRAM1, ENABLE); } #fcsm-lcd
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    2 replies

    Peter Lissenburg
    Associate III
    April 17, 2013
    Posted on April 17, 2013 at 09:57

    Sorry for the noise. Found the problem.

    Was using

    //#define LCD_REG              (*((volatile unsigned short *) 0x60000000)) /* RS = 0 */

    //#define LCD_RAM              (*((volatile unsigned short *) 0x60010000)) /* RS = 1 */

    Changed to

    #define LCD_REG              (*((volatile unsigned char *) 0x60000000)) /* RS = 0 */

    #define LCD_RAM              (*((volatile unsigned char *) 0x60010000)) /* RS = 1 */

    So now, for example

    LCD_REG = ST7735S_SWRESET;

    sends only one byte.

    Cheers.

    Pete L.

    yuriy_99
    Visitor II
    November 24, 2013
    Posted on November 24, 2013 at 21:35

    Pete L., Thank You!!!

    The same problem, and this code helped me