Hi, I observe a strange behavior when I perform a binary read of more than 128KB (almost 140KB) from SD card to external SRAM memory at 0x2800000. Everything works well for the firsts 128KB but from here on 0x2800000 address memory and above are overwritten with wrong data. It really puzzles me.
More hints: - RL-ARM Rev.: V4.12 - 256KB of external SRAM buffer size - FAT16 SD format
IDE-Version: µVision V4.14.4.0 Copyright (C) 2010 KEIL(TM) Tools by ARM
Tool Version Numbers: Toolchain: RealView MDK-ARM Version: 4.14 Toolchain Path: BIN40\ C Compiler: Armcc.Exe V4.1.0.567 Assembler: Armasm.Exe V4.1.0.567 Linker/Locator: ArmLink.Exe V4.1.0.567 Librarian: ArmAr.Exe V4.1.0.567 Hex Converter: FromElf.Exe V4.1.0.567 CPU DLL: SARM.DLL V4.14 Dialog DLL: DARMST9.DLL V1.07 Target DLL: BIN\UL2ARM.DLL V1.64 Dialog DLL: TARMST9.DLL V1.08
Could anybody help me? Thanks in advance, Gaston
Hi Gaston,
Like Per is saying - it looks like a decoding problem. There could be several reasons:
- incorrect configuration of the memory controller - incorrect timing - schematic errors - HW problem (shorted traces or pins/balls)
Andrew
Andrew, Per, I've gone back again to my code and I found that A16 and A17 were not configured as EMI outputs (Alternate 2 function). I've changed the code to add this configuration and now it works as I expected! Thank you very much for your help.
Regards, Gaston