无论是对DDR3存储器进行调试还是进行一致性测试,都需要首先将读和写操作分离开,以对每种不同的操作模式分别进行测量。DDR3的读写分离作为DDR最基本也是最常用的部分,一起来看案例。 上期回顾《计算机主板DDR3时序信号完整性案例-CLK 与 Command&Adress》 应用案例: DQS&DQ(Write) DQ3: DQ10: 信号完整性与电源...
源端同步发送的时钟信号 CK 和数据有效信号 DQS 在接收端出现了偏差,一般来说时钟信号会更滞后一些。从 DRAM 端返回的 DQ 值为 0,表示 DQS 上升沿时 CK 信号为低电平。源端 MC 根据 DQ 数值,继续加大 DQS 的延迟,直至 DQ 值为 1,此时 DQS 上升沿时 CK 信号为高电平。再略微将延迟调小,MC 就捕捉到...
parameter int DDR3_WDQ_PHASE = 270, // 270, Select the write and write DQS output clock phase relative to the DDR3_CLK/CK# BrianHG_DDR3_PLL.sv Version 1.2, August 26, 2021: Added support for Cyclone V / Arria V / Stratix V style PLL support. How to achieve the full 400MHz FMA...
PySimpleGUI is an odd duck when it comes to how it uses these packages. I'm in a constant state of entering and hard-exiting event loops, with the expectation that tkinter and the others will properly manage their event queues regardless of whether or not they have control of the CPU at...
The DDR2 HPC goes through a calibration sequence on startup where it tries to determine the proper alignment for DQ/DQS signals. If it fails to achieve this, it will essentially never accept transactions on its interface. One way to check for this is to look at the "local_init_don...
Since the damping resistor(10ohm) are inserted in the DQS/DQ line, the number of VIA have increased. The customer are checking the Board_delay() and going to test with lower PLL frequency right now. best regards, g.f. 4401.C6678 DDR3 Write issue.pdf ...
The HPCII seems to be the same for DDR2 so I use similar vhdl code to manage the local interface. I do a simple test: write 4x32bit and then read it back. Both simulation and signal tap give the same result, read data are wrong. The simulation shows that dq/dqs signals are ...
1.17.5. Stage 2: Write Calibration Part One External Memory Interface Handbook Volume 3: Reference Material: For UniPHY-based Device Families Download PDF
DQS&DQ(Write) DQ3: DQ10: 信号完整性与电源完整性分析 LDQS: UDQS: DQS&DQ(Read) DQ3: DQ10: LDQS: UDQS: 更多信号完整性量测, 详询启威测。 简介 启威测是一家专注于电子产品及材料研发阶段可靠性检测、验证及失效分析服务的第三方检测机构。网址:www.qwctest.com,联系电话:0755-27403650。
The present invention is related to dynamic random access memory (DRAM) devices. In particular, it relates to a system and method for improving a DRAM's ability to capture data correctly on all data paths (DQs). 2. Description of Related Art ...