External Memory Interface Handbook Volume 3: Reference Material: For UniPHY-based Device Families

ID 683841
Date 3/06/2023
Public
Document Table of Contents

2.4.6. Stratix® 10 EMIF Architecture: Input DQS Clock Tree

The input DQS clock tree is a balanced clock network that distributes the read capture clock and strobe from the external memory device to the read capture registers inside the I/Os.

You can configure an input DQS clock tree in x4 mode, x8/x9 mode, x18 mode, or x36 mode.

Within every bank, only certain physical pins at specific locations can drive the input DQS clock trees. The pin locations that can drive the input DQS clock trees vary, depending on the size of the group.

Table 23.  Pins Usable as Read Capture Clock / Strobe Pair
Group Size Index of Lanes Spanned by Clock Tree In-Bank Index of Pins Usable as Read Capture Clock / Strobe Pair
Positive Leg Negative Leg
x4 0A 4 5
x4 0B 8 9
x4 1A 16 17
x4 1B 20 21
x4 2A 28 29
x4 2B 32 33
x4 3A 40 41
x4 3B 44 45
x8 / x9 0 4 5
x8 / x9 1 16 17
x8 / x9 2 28 29
x8 / x9 3 40 41
x18 0, 1 12 13
x18 2, 3 36 37
x36 0, 1, 2, 3 20 21