A quick comparison shows these two SDRAM parts should be identical for the config used in the SEMC demo app...
Any hints / ideas from SDRAM experts on what could be causing uint32_t access to fail while uint16_t and uint8_t are working fine?
status_t BOARD_InitSEMC(void)
{
semc_config_t config;
semc_sdram_config_t sdramconfig;
uint32_t clockFrq = EXAMPLE_SEMC_CLK_FREQ;
/* Initializes the MAC configure structure to zero. */
memset(&config, 0, sizeof(semc_config_t));
memset(&sdramconfig, 0, sizeof(semc_sdram_config_t));
/* Initialize SEMC. */
SEMC_GetDefaultConfig(&config);
config.dqsMode = kSEMC_Loopbackdqspad; /* For more accurate timing. */
SEMC_Init(SEMC, &config);
/* Configure SDRAM. */
sdramconfig.csxPinMux = kSEMC_MUXCSX0;
sdramconfig.address = 0x80000000;
sdramconfig.memsize_kbytes = 32 * 1024; /* 32MB = 32*1024*1KBytes*/
sdramconfig.portSize = kSEMC_PortSize16Bit;
sdramconfig.burstLen = kSEMC_Sdram_BurstLen8;
sdramconfig.columnAddrBitNum = kSEMC_SdramColunm_9bit;
sdramconfig.casLatency = kSEMC_LatencyThree;
sdramconfig.tPrecharge2Act_Ns = 18; /* Trp 18ns */
sdramconfig.tAct2ReadWrite_Ns = 18; /* Trcd 18ns */
sdramconfig.tRefreshRecovery_Ns = 67; /* Use the maximum of the (Trfc , Txsr). */
sdramconfig.tWriteRecovery_Ns = 12; /* 12ns */
sdramconfig.tCkeOff_Ns =
42; /* The minimum cycle of SDRAM CLK off state. CKE is off in self refresh at a minimum period tRAS.*/
sdramconfig.tAct2Prechage_Ns = 42; /* Tras 42ns */
sdramconfig.tSelfRefRecovery_Ns = 67;
sdramconfig.tRefresh2Refresh_Ns = 60;
sdramconfig.tAct2Act_Ns = 60;
sdramconfig.tPrescalePeriod_Ns = 160 * (1000000000 / clockFrq);
sdramconfig.refreshPeriod_nsPerRow = 64 * 1000000 / 8192; /* 64ms/8192 */
sdramconfig.refreshUrgThreshold = sdramconfig.refreshPeriod_nsPerRow;
sdramconfig.refreshBurstLen = 1;
return SEMC_ConfigureSDRAM(SEMC, kSEMC_SDRAM_CS0, &sdramconfig, clockFrq);
}
Actually - testing with the descriptors worked for me for a few times, but eventually 32 bit accesses begin to fail as well, giving read output like so (instead of 0, 1, 2, 3, 4, ...:
What I found was that if I don't set "Reset on Connect" in the LinkServer Debugger options - then 32 bit accesses work when I re-run the app, but if I do set "Reset on Connect", then 32 bit accesses fail...
Further testing shows that if I just write garbage to SDRAM, and then read back - then subsequent writes and reads work to areas that had previously been accessed (on the MT device)...
