2013-07-21 07:59 PM
I'm using a SRAM and 74LVC138 for addressing external IOs in address 80000H. The code example works well with SRAM, but I can not access the IOs. The pin A19 seems to be dead when I try to write at address 80000H. Thanks if anyone can help. Below is the startup code FSMC. I am using the example code from ST.
/*-- FSMC Configuration ------------------------------------------------------*/ p.FSMC_AddressSetupTime = 1; p.FSMC_AddressHoldTime = 0; p.FSMC_DataSetupTime = 2; p.FSMC_BusTurnAroundDuration = 0; p.FSMC_CLKDivision = 0; p.FSMC_DataLatency = 0; p.FSMC_AccessMode = FSMC_AccessMode_A; FSMC_NORSRAMInitStructure.FSMC_Bank = FSMC_Bank1_NORSRAM2; FSMC_NORSRAMInitStructure.FSMC_DataAddressMux = FSMC_DataAddressMux_Disable; //FSMC_NORSRAMInitStructure.FSMC_DataAddressMux = IS_FSMC_MUX(0); FSMC_NORSRAMInitStructure.FSMC_MemoryType = FSMC_MemoryType_SRAM; FSMC_NORSRAMInitStructure.FSMC_MemoryDataWidth = FSMC_MemoryDataWidth_16b; FSMC_NORSRAMInitStructure.FSMC_BurstAccessMode = FSMC_BurstAccessMode_Disable; FSMC_NORSRAMInitStructure.FSMC_AsynchronousWait = FSMC_AsynchronousWait_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_SRAM2 Bank */ FSMC_NORSRAMCmd(FSMC_Bank1_NORSRAM2, ENABLE); #stm32 #fsmc2013-07-22 08:05 AM
What about pin A18? Or with an offset at +0x100000?
Doesn't the address bus get shifted with 16-bit accesses?2013-07-22 06:50 PM
Correct. I was using 16-bit addressing (FSMC_MemoryDataWidth = FSMC_MemoryDataWidth_16b) and forgot that the bus is shifted . Switching to 8-bit addressing works correctly. Thanks.