stm32f429主頻為180MHz,?sdramz做lcd緩存時,刷完一幀圖片，部分像素點顏色發送了變化，如下圖。但將主頻設置為160MHz時圖片顯示又很穩定，后來測試了一下sdram，發現主頻大于160M,并且隨著主頻的增大，sdram的數據越不穩定。而160M時數據又很穩定，有沒有人遇到這樣的問題呢？會不會是sdram的布線不好引起的？

sdram配置如下：

[mw_shl_code=c,true]/* FMC SDRAM Bank configuration */

/* Timing configuration for 90 Mhz of SD clock frequency (180Mhz/2) */

/* TMRD: 2 Clock cycles */

FMC_SDRAMTimingInitStructure.FMC_LoadToActiveDelay = 2;

/* TXSR: min=70ns (7x11.11ns) */

FMC_SDRAMTimingInitStructure.FMC_ExitSelfRefreshDelay = 7;

/* TRAS: min=42ns (4x11.11ns) max=120k (ns) */

FMC_SDRAMTimingInitStructure.FMC_SelfRefreshTime = 4;

/* TRC: min=70 (7x11.11ns) */

FMC_SDRAMTimingInitStructure.FMC_RowCycleDelay = 7;

/* TWR: min=1+ 7ns (1+1x11.11ns) */

FMC_SDRAMTimingInitStructure.FMC_WriteRecoveryTime = 2;

/* TRP: 20ns => 2x11.11ns */

FMC_SDRAMTimingInitStructure.FMC_RPDelay = 2;

/* TRCD: 20ns => 2x11.11ns */

FMC_SDRAMTimingInitStructure.FMC_RCDDelay = 2;

/* FMC SDRAM control configuration */

FMC_SDRAMInitStructure.FMC_Bank = FMC_Bank2_SDRAM;

/* Row addressing: [7:0] */

FMC_SDRAMInitStructure.FMC_ColumnBitsNumber = FMC_ColumnBits_Number_8b;

/* Column addressing: [11:0] */

FMC_SDRAMInitStructure.FMC_RowBitsNumber = FMC_RowBits_Number_12b;

FMC_SDRAMInitStructure.FMC_SDMemoryDataWidth = SDRAM_MEMORY_WIDTH;

FMC_SDRAMInitStructure.FMC_InternalBankNumber = FMC_InternalBank_Number_4;

FMC_SDRAMInitStructure.FMC_CASLatency = SDRAM_CAS_LATENCY;

FMC_SDRAMInitStructure.FMC_WriteProtection = FMC_Write_Protection_Disable;

FMC_SDRAMInitStructure.FMC_SDClockPeriod = SDCLOCK_PERIOD;

FMC_SDRAMInitStructure.FMC_ReadBurst = SDRAM_READBURST;

FMC_SDRAMInitStructure.FMC_ReadPipeDelay = FMC_ReadPipe_Delay_1;

FMC_SDRAMInitStructure.FMC_SDRAMTimingStruct = &FMC_SDRAMTimingInitStructure;[/mw_shl_code]

bd1fa35bcce5b69d939ec48de2ffbbe3_15.jpg (0 Bytes, 下載次數: 15)

2010-12-14 22:54 上傳

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