i.MX Processors中的主题 Re: i.MX8M Mini DDR Package trace length/delay

i.MX8M Mini DDR Package trace length/delay

shruthi_subrama — Wed, 29 May 2019 09:50:34 GMT

Hi,

We designing i.MX8M Mini custom board using LPDDR4 memory. For LPDDR4 length match, we need to consider i.MX 8M Mini DDR package trace delays(ps)-which is given in picosec as per Table 27 in i.MX 8M Mini Hardware Developer’s Guide.

We need to get information on IMx8MMini DDR Package trace length in microns/mils for DDR length match in our board.

How can i convert IMx8MMini DDR Package Trace delay from ps to trace length in mils/micron. Please help and support us.

Regards

Shruthi

Re: i.MX8M Mini DDR Package trace length/delay

art — Fri, 31 May 2019 11:57:02 GMT

The actual in-package wire length data is not useful in your case since the signal fly time on in-package wire may differ from the on-board trace signal fly time.

You can calculate the virtual trace length deltas for each DDR interface signal based on known on-board trace signal fly time per unit of length and the in-package signal propagation delay times, given in the Table 27.

Have a great day,
Artur

Re: i.MX8M Mini DDR Package trace length/delay

dennisespey — Sun, 05 Apr 2020 23:20:33 GMT

Most are aware of the DDRx timing constraints and PCB+package bondwire implications. Those lengths are in Table 27 of teh design guide. What about for other high speed signals?

I intend to use the FlexSPI in Octal mode to an FPGA. The DDR transfer mode is at 166MHz (max). The timing looks quite tight.

Can NXP provide package bond wire length for all pins? DDR, FlexSPI, and beyond? Xilinx provides this for all pins, all current devices.

In particular, I am using the MIMX8MM3CVTKZAA.

Stay safe,

Dennis