I'm currently setting up a STM32F407 to evaluate a display module which utilizes a Renesas R61526A Displaycontroller.
I was able to set up the project using CubeMX no problem, and the FSMC seems to be working.
However I noticed that the output data word was big endian, yet im pretty sure all STM32 are little endian (uint16_t 0x51ab as variable becomes 0xab51 when monitoring D0-16 output with the scope). I did not expect the FSMC to change the byte order on the output.
#define LCDADDRESS 0x63FFF00F
const LCDmemorymapping LCDRWregisteraccess = (uint16_t*) LCDADDRESS;
static void writetoLCD(uint16_t dataword)
{
*LCDRWregisteraccess= (uint16_t) dataword;
}
static uint16_t readfromLCD(uint16_t unused)
{
return (uint16_t) *LCDRWregisteraccess;
}
/* FSMC initialization function */
static void MX_FSMC_Init(void)
{
FSMC_NORSRAM_TimingTypeDef Timing;
/** Perform the SRAM1 memory initialization sequence
*/
hsram1.Instance = FSMC_NORSRAM_DEVICE;
hsram1.Extended = FSMC_NORSRAM_EXTENDED_DEVICE;
/* hsram1.Init */
hsram1.Init.NSBank = FSMC_NORSRAM_BANK1;
hsram1.Init.DataAddressMux = FSMC_DATA_ADDRESS_MUX_DISABLE;
hsram1.Init.MemoryType = FSMC_MEMORY_TYPE_SRAM;
hsram1.Init.MemoryDataWidth = FSMC_NORSRAM_MEM_BUS_WIDTH_16;
hsram1.Init.BurstAccessMode = FSMC_BURST_ACCESS_MODE_DISABLE;
hsram1.Init.WaitSignalPolarity = FSMC_WAIT_SIGNAL_POLARITY_LOW;
hsram1.Init.WrapMode = FSMC_WRAP_MODE_DISABLE;
hsram1.Init.WaitSignalActive = FSMC_WAIT_TIMING_BEFORE_WS;
hsram1.Init.WriteOperation = FSMC_WRITE_OPERATION_ENABLE;
hsram1.Init.WaitSignal = FSMC_WAIT_SIGNAL_DISABLE;
hsram1.Init.ExtendedMode = FSMC_EXTENDED_MODE_DISABLE;
hsram1.Init.AsynchronousWait = FSMC_ASYNCHRONOUS_WAIT_DISABLE;
hsram1.Init.WriteBurst = FSMC_WRITE_BURST_DISABLE;
hsram1.Init.PageSize = FSMC_PAGE_SIZE_NONE;
/* Timing */
Timing.AddressSetupTime = 3;
Timing.AddressHoldTime = 15;
Timing.DataSetupTime = 8;
Timing.BusTurnAroundDuration = 3;
Timing.CLKDivision = 16;
Timing.DataLatency = 17;
Timing.AccessMode = FSMC_ACCESS_MODE_A;
/* ExtTiming */
if (HAL_SRAM_Init(&hsram1, &Timing, NULL) != HAL_OK)
{
_Error_Handler(__FILE__, __LINE__);
}
}
I would like the output to be little-endian as well, so am I doing something obviously wrong ? The obvious solution would be to read/write the data as
*LCDRWregisteraccess= (uint16_t)((0xff00&dataword)>>8)|(0x00ff&dataword<<8));
or to just use the REV16 instruction but I was wondering whether there is a configuration within the FSMC that I'm missing or something else I'm doing wrong.
Also this is my first stack exchange question, so if I didn't formulate the question correctly, please feel free to point it out :)
Many thanks in advance!
