I am debugging DDR3 (micron M$41k512M16HT using dummy register write and read. When I write a number 0xFFFFFFFF, i got the number 0x00000000 in all the 8 dummy read registers. When I write a number 0x00550055, I get the number 0xAAAAAAAA,0xFFFFFFFF,0xAAAAAAAA,0xFFFFFFFF,0xAAAAAAAA,0xFFFFFFFF,0xAAAAAAAA,0xFFFFFFFF.
when I write a number 0xAAAAAAAA, i get the number 0x55555555 in all 8 dummy register. When I write a number 0xAB5DC432, I got the number 0xCDCDCDCD, 0x3B3B3B3B, 0xA2A2A2A2,0x54545454. It seems that erery dummy register hold one byte inverted of the write value. The ZQCL and write level calibration can be passed. somethings wrong with my settings?
I saw a line in the reference manual in the DQS gating calibration section :
atep 9: MMDC reset the read FIFO (to the inverted pre-defined/MPR value), what does this mean?
below is a piece of my test code:
CMD=(0x02<<4); //one refresh command send to DDR
HW_MMDC_MDSCR_WR(MMDC1_BASE,CON_REQ|CMD_CS|CMD); //DDR refresh
while(!((HW_MMDC_MDSCR_RD(MMDC1_BASE))&0x00004000))
{
}
CMD=(0x05<<4);
HW_MMDC_MDSCR_WR(MMDC1_BASE,CON_REQ|CMD|CMD_CS); //pre-charge all banks
while(!((HW_MMDC_MDSCR_RD(MMDC1_BASE))&0x00004000))
{
}
PDV2=(0xAC5D<<16);
PDV1=0xC432;
HW_MMDC_MPPDCMPR1_WR(MMDC1_BASE, PDV1|PDV2); //set pre-defined value which will be written to DDR device
SW_DUMMY_WR=1;
HW_MMDC_MPSWDAR0_WR(MMDC1_BASE,SW_DUMMY_WR); //write predefined value to DDR bank 0, row 0 col 0
while ((HW_MMDC_MPSWDAR0_RD(MMDC1_BASE)&0x00000001))
{
}
RST_RD_FIFO=(0x1<<31);
HW_MMDC_MPDGCTRL0_WR(MMDC1_BASE,RST_RD_FIFO);
while((HW_MMDC_MPDGCTRL0_RD(MMDC1_BASE)&0x80000000))
{
} //wait fifo reset
HW_MMDC_MPDGCTRL0_WR(MMDC1_BASE,RST_RD_FIFO); //reset rd fifo second times
while((HW_MMDC_MPDGCTRL0_RD(MMDC1_BASE)&0x80000000))
{
} //wait fifo reset
HW_MMDC_MPSWDAR0_WR(MMDC1_BASE,0x02); //read value from to DDR bank 0, row 0 col 0
while ((HW_MMDC_MPSWDAR0_RD(MMDC1_BASE)&0x00000002))
{
}
readValue8=HW_MMDC_MPSWDAR0_RD(MMDC1_BASE);
readValue=HW_MMDC_MPSWDRDR0_RD(MMDC1_BASE);
readValue1=HW_MMDC_MPSWDRDR1_RD(MMDC1_BASE);
readValue2=HW_MMDC_MPSWDRDR2_RD(MMDC1_BASE);
readValue3=HW_MMDC_MPSWDRDR3_RD(MMDC1_BASE);
