Team,
Can someone help with AM437x SDMMC? Customer is trying to verify SDMMC interface using GEL file (excerpt below). They are not getting successful read when running CMD19/CMD14.
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** cannot successfully send CMD14:
All we wondered is about clarification on how to use that SD_DATA register, which isn't self-explanatory to me. In addition, I couldn't successfully send CMD14 (test read) after issuing CMD19 (test write). It seems I couldn't write to DDIR bit of SD_CMD register while Buffer Write Enable bit of SD_PASTATE[10] is set.
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** how to use SD_DATA register 'mbyteen[] ...'
an expert on MMC controller as I just need some clarification of how to use (read/write) the SD_DATA register as I couldn't fully understand the wording in TRM.
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hotmenu eMMC_Bus_Initialization()
{
UWORD32 i;
// /* Set MMC clock freq to 100KHz (might need a different frequency though) */
// WR_MEM_32(MMC1_SYSCTL, RD_MEM_32(MMC1_SYSCTL) | 0xF000); // ref clk = 96Mhz; divider = 600 = 0x258 (then right shift by two)
/* send CMD1 and check commmand complete (CC) bit in SD_STAT */
do
{
MMC_CMD_SEND(1, 0xC0FF8080, RSP_R3);
/* wait 1 ms */
// for (i = 0; i < 100; i= i + 1) {} // It seems the while loop by itself takes 80ms to resend CMD1
} while (RD_MEM_32(MMC1_RSP10) != 0xC0FF8080); // SD_STAT[0] Command Complete bit doesn't seem to work so we check OCR in RSP10 instead.
// GEL_TextOut("CMD1 command sent successfully. Sending CMD2...\n");
/* send CMD2 for CID (R2 response)*/
MMC_CMD_SEND(2,0,RSP_R2); // CID request
/* poll command complete (CC) bit of STAT register */
// while(RD_MEM_32(MMC1_STAT) & 0x1 != 0x1);
if (RD_MEM_32(MMC1_RSP76) >> 16 == 0x7001)
{
GEL_TextOut("Identified: Kingston eMMC BGA Package.\n");
}
else if (RD_MEM_32(MMC1_RSP76) >> 16 == 0x1101)
{
GEL_TextOut("Identified: Toshiba eMMC BGA Package.\n");
}
else if (RD_MEM_32(MMC1_RSP76) >> 16 == 0xFE01)
{
GEL_TextOut("Identified: Micron eMMC BGA Package.\n");
}
else
{
GEL_TextOut("Unknown eMMC device.\n");
}
/* send CMD3 to assign RCA (0x1) */
MMC_CMD_SEND(3,0x10000,RSP_R1); //
/* send CMD9 to ask for Device Specific Data (CSD) */
MMC_CMD_SEND(9, 0x10000, RSP_R2); // R2 response
/* CMD7 select card to enter transfer mode */
MMC_CMD_SEND(7, 0x10000, RSP_R1);
/* CMD8 read EXT_CSD register */
// WR_MEM_32(MMC1_BLK, 0x200); // set block length of 512 bytes (single block)
// MMC_CMD_SEND(8, 0, RSP_R1); // argument = 0, response type = R1, DataPresent=1
// while (RD_MEM_32(MMC1_PSTATE) & 0x800 != 0x800)
/* CMD6 to modify bus width of eMMC to 8 bit*/
MMC_CMD_SEND(6, ((3<<24) | (183<<16) | (2<<8)), RSP_R1B);
/* set DW8 of SD_CON to enable 8 bit mode for host */
WR_MEM_32(MMC1_CON, RD_MEM_32(MMC1_CON) | 0x20);
/* send CMD19 to test write data patern on 8 bit bus */
MMC_CMD_SEND(19, 0, RSP_R1);
while((RD_MEM_32(MMC1_PSTATE) >> 10) & 0x1 == 0);
MMC_CMD_SEND(MMC1_DATA, 0x0000);
while((RD_MEM_32(MMC1_PSTATE) >> 10) & 0x1 == 0);
MMC_CMD_SEND(MMC1_DATA, 0x0000);
while((RD_MEM_32(MMC1_PSTATE) >> 10) & 0x1 == 0);
MMC_CMD_SEND(MMC1_DATA, 0x0000);
while((RD_MEM_32(MMC1_PSTATE) >> 10) & 0x1 == 0);
MMC_CMD_SEND(MMC1_DATA, 0xAA55);
/* send CMD14 to test read data pattern from the eMMC device */
MMC_CMD_SEND(14, 0, RSP_R1);
// GEL_TextOut("Module runs SDIO interface.\n");
}
