Incorrect Range for Command Queue Look-Ahead Depth in ALTMEMPHY-Based Interfaces

This problem affects DDR, DDR2, and DDR3, ALTMEMPHY-based products.

For ALTMEMPHY-based products, the memory controller incorrectly shows the valid values for the Command Queue Look-ahead Depth to be 0, 2, 4, 8. In reality, 0 is not a valid value. The correct range of values is 1–16.

The workaround for this issue is to limit yourself to 2, 4, 8, or to modify a line in the generated wrapper file, as described below:

In the file <instance_name>_alt_mem_ddrx_controller_top.v, change the following line:

localparam CFG_CTL_TBP_NUM = CTL_TBP_NUM;

to

localparam CFG_CTL_TBP_NUM = <desired value from 1–16>;

This issue will not be fixed.