t1040 ddr4 about odt question

[于立冬]

In t1040 reference manual chapter 14 Table 14-3. Memory Address Signal Mappings for DDR4   ，It list modt1 to odt1  no introduce modt0 to odt0   。  if I USE DDR4 CLK0  and cke0 to design(no dimm)，zhe odt  used odt 0 ? I think  the table have  different interpretations

[ufedor]

Missing MODT0 in the table is a typo.

For the discrete DDR4 SDRAM design please refer to the T1023RDB-PC schematics in the design files:

http://cache.nxp.com/downloads/en/printed-circuit-boards/T1023RDB-PC-DS.zip?fsrch=1&sr=4&pageNum=1 

[于立冬]

T1023  RDB  is ddr4 x8 * 4 =32bit  it have two cke  odt，if I want to use ddr4 X16(it have only  one  odt  cke)  I must use cke0 odt0  not cke 1,odt 1 when use clk0?

[ufedor · Accepted solution]

Please refer to the T1040 Family Design Checklist, Rev. 1:

"For a single, dual-ranked DIMM, consider the following connections

• MODT(0), MCS(0), MCKE(0)
• MODT(1), MCS(1), MCKE(1)"

So for a single rank you have to use MODT(0), MCS(0), MCKE(0).