ALTDQ_DQS2 IP Core User Guide

ID 683742
Date 5/08/2017
Public
Document Table of Contents

Understanding Simulation Results—Stratix V Design Example

ln the Stratix V design example, a generic testbench is used to test the write and read operations in the ALTDQ_DQS2 IP core. The following table lists the components in the testbench.

Table 11.  Testbench Components
Component Description
DQS Driver
  • Acts as a host controller, sends read/write commands to the ALTDQ_DQS2 IP core.
  • Compares data read back from a DQS agent to what it should be.
  • Has a side channel (side reads/writes) communicating directly with the DQS agent, bypassing the ALTDQ_DQS2 IP core. Use the data in the side reads/writes to compare with the data sent to or received from the ALTDQ_DQS2 IP core.
DQS Agent
  • Acts as an external memory device.
  • Has a side channel (side reads/writes) communicating directly with the DQS driver, bypassing the ALTDQ_DQS2 IP core. Use the data in the side reads/writes to compare with the data sent to or received from the ALTDQ_DQS2 IP core.
Note: Random data is generated and used in the testbench. You may see other data values if you are using a different operating system and seeds.

The following figure shows the waveform for the testbench generated after executing the top_run_msim_rtl_verilog.do file.

Figure 19. Waveform Example


All ports are in reset mode until the reset_n signal is asserted at 70 ns. Then, the core_clk_fr and core_clk_hr clocks start to toggle. The agent_reset_n_to_dqs signal is asserted at 91 ns to reset the ALTDQ_DQS2 IP core, which is located in top_inst.