Type: Answers, Errata

Area: EMIF, Intellectual Property



Refresh to Precharge Command Timing Violation

Description

ALTMEMPHY-based designs created with a version of the high-performance controller (HPC II) earlier than 11.0, with the Enable User Auto Refresh Controls option turned on, violate refresh to precharge command timing, breaching JEDEC requirement.

This issue affects all designs created in a pre-11.0 version of HPC II, with the Enable User Auto Refresh Controls option turned on.

Your design fails to simulate and doesn’t work in hardware.

Workaround/Fix

To meet the JEDEC requirement, perform the following steps:

  1. Open the alt_ddrx_bank_timer.v file.
  2. Locate the following command:
  3. cs_can_precharge_all [w_cs] = chip_idle;

    and change to:

    cs_can_precharge_all [w_cs] = power_saving_enter_ready [w_cs] & chip_idle;

This issue will be fixed in a future version.