topic Re: t1040 ddr4 about odt question in T-Series

t1040 ddr4 about odt question

于立冬 — Wed, 02 Aug 2017 02:51:55 GMT

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

Re: t1040 ddr4 about odt question

ufedor — Wed, 02 Aug 2017 06:40:33 GMT

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

Re: t1040 ddr4 about odt question

于立冬 — Wed, 02 Aug 2017 07:18:50 GMT

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?

Re: t1040 ddr4 about odt question

ufedor — Wed, 02 Aug 2017 10:16:29 GMT

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).