Ddr3 data swapping. DDR2, DDR3, DDR4, or LPDDR4 design and layout.

Ddr3 data swapping. However, many users are unsure if they can simply switch out their existing RAM with new modules. can I swap the pin outs of the data in controller within the byte ,If swaping is done do I have to modify any thing in the software or straight away Hi I can not find any guides on DDR4 bit swap for Xilinx ultrascale devices, for Ultrascale and Ultrascale\+ it seems that bit swap withing a byte lane is fully OK as Vivado does not constrain the bits within a lane. This increased data bus performance is due to source-synchronous data strobes that May 20, 2025 · Over the years, RAM technology has evolved, and two of the most popular types are DDR3 (Double Data Rate 3) and DDR3L (Low Voltage DDR3). The Virtex-6 FPGA Memory Solutions User Guide (UG406) states the following allowed changes for moving pins in the design generated by MIG: The address and control pin assignments can be May 25, 2022 · The routing between the DDR3 and processor is on internal layers, so the routing from the DDR3 vias to the VTT termination resistors essentially create 'stubs' on the bottom of the board. I attached a image file it shows ddr3 schematic design,why aren't the names in the SDQ nets in order?can we design the data section in ddr memories as we wish? just swap nets with each other?if this is true, i have no justification for it😟 grrmachine , 06-14-2020, 03:59 PM Hi @kazemiy974 On a XC7Z020-1CLG484C FPGA I am using the pre-packaged IP DDR3 memory controller off the Zynq processor. For DDR3(L) memories such reading is not used. 2), the tools include Basicaly no is a good answer. Jul 24, 2014 · Hi, We are developing a custom board based on the imx6sl evolution kit. I am using freescale processor P2041 connected to a 5-16 bit micron chips (one chip 8-bit for ECC) there are some criss cross in routing . e, all signals within a byte of the TDA2x must be routed to the same byte of the DDR2/3 memory). DQ0 for each end of the link per byte is reserved for this purpose. 1 Bit and Byte Swapping DDR3 and DDR2 memories support bit swapping, a technique the designer can use to interchange data lines with one another, provided that they correspond to the same byte lane (for example, any bits inside the D [0. Here are some rules for SDRAM chips. 5. Does the DDR3 data swapping have any limitations **BEST SOLUTION** Address pins are used to write the configuraton registers of the DDR3 memory chips. You cannot swap a DQ lane with an AC lane. What you can't do is swap bits across byte lanes. i found the SDB board has swap May 29, 2024 · I am trying to connect a two DDR3 to a Zynq FPGA. Since these pins are fixed on Zynq there Nov 3, 2020 · For swapping data line of DDR3, according to the “Hardware Development Guide”, it said ‘No restrictions for complete byte lane swapping’ and ‘D0, D8, D16, D24, D32, D40, D48, and D56 are fixed’. can I swap the pin outs of the data in controller within the byte ,If swaping is done do I have to modify any thing in the software or straight away Mar 16, 2017 · As we can see data is not read back in correct order. JEDEC doesn’t specify on which data bit the controller expects the feedback from the memory, so the controller should be able to receive it on any data bit, allowing pin swapping. MX 6SoloLite" : The rules are as follows: • Hardware write leveling – lowest order bit within byte lane must remain on lowest order bit of lane by JEDEC compliance (see the “Write Leveling” section in JES Yes, it is okay to swap DQ bits within the same byte on the TDA2x DDR2/DDR3 interface. can I swap the pin outs of the data in controller within the byte ,If swaping is done do I have to modify any thing in the software or straight away Apr 28, 2015 · I had gone through the ddr3 guidlines by freescale I could'nt find any constrains on no of layers for routing. Is there need of any register change needed in imx6 mmdc registers ? We have done DDR configuration with help of I MX6 DDR3 script Aid. Sep 13, 2021 · I am designing a DDR3 interface to a Xilinx Kintex Ultrascale FPGA. This is valid only to the data (DQ) signals. Note that the DQ signal cannot be swapped between data We would like to show you a description here but the site won’t allow us. 4 Pin Swap · DDRx应用指南 Dec 7, 2020 · we are working with a custom board, that implemented data lines swapping, the note says target DDR IC register read value must be transposed according to the data line swapping. e. The MIG tool follows these rules: Apr 24, 2015 · I had gone through the ddr3 guidlines by freescale I could'nt find any constrains on no of layers for routing. 7) / (8. However, "AM4376: DDR3 prime bit swapping" says that it is possible to swap within byte lane including prime bits. As the name implies, DDR enables two data transactions to occur within a single clock cycle without doubling the applied clock or without to doubling the size of the data bus. of my ddr3 connection with imx6sl. It does not require to modify any thing in the software. PS DDR drivers do not have discrete settings for drive strength or slew rate. Nov 13, 2024 · Pins can be freely swapped within each byte group (data and address/control), except for the DQS pair which must be on a clock-capable DQS pair and the CK, which must be on a clock-capable DQS pair. The DQSn pins in DDR2 SDRAM devices are optional but recommended for DDR2 SDRAM designs operating at more than 333 MHz. to make the layout more easier, I want to swapping data lines. If the pin-out generated by MIG does not follow the desired pin-out on my board, how can the design be modified? Starting with MIG 7 Series 1. Is it possible to swap control signals such as addresses, other than data? 5. The FPGA is connected to two separate DDR3 chips which share address, command, and control lines using flyby topology. But you can't do what you did: swap bits arbitrarily within the 16 bit bus. Apr 1, 2015 · hi Freescale: our board design is base on SDB board,the OS is Android4. • DQ byte lane swapping is allowed. can I swap the pin outs of Nov 18, 2020 · Is it possible to swap "Data Mask" or "Data Strobe" pins with DQx pins within the same byte lane. Please suggest the hardware and software changes. the data bus is used to comunicate commands to the ddr3 chips ! so if you twiddle the data bus around, you twiddle the commands, not a good idea. Is there Jun 22, 2023 · Hi, We design a custom i. Hence chip manufacturers/JEDEC provisioned data bit/byte swapping. Here I wrote down my own bootstrap on learning DDR3 jargons and way up to design and understand underline rationale behind the DDR3 length matching. They need to be in sequence. as I former experience , the data line on DDR3 component side, can be swapping but only within one byte. I had swap some data pins with some DDR_DMx pins as shown in the pictures. In Freescale's "Hardware and Layout Design Considerations for DDR3 SDRAM M Jun 18, 2025 · Swapping RAM sticks can pose several risks, including system crashes, instability, or even damage to the hardware. 23) / (24. Is it possible to swap control signals such as addresses, other than data? Apr 24, 2015 · I had gone through the ddr3 guidlines by freescale I could'nt find any constrains on no of layers for routing. I looked at the I/O ports selection gui in "ELABORATED DESIGN" and it seems like they are fixed. The tool does not allow users to select the specific pins within those byte groups. I've attac. DDR_DQxx are data pins and DDR_DMx are connected to DM pins. Is it mandatory to follow same EVK data line swapping connection to our Design? then why its required? Q2. Pins in the address/control byte groups can Jun 23, 2023 · We design a custom i. only swap byte0 with byte1 is possible, byte2 and byte3 are left open). I attached a image file it shows ddr3 schematic design,why aren't the names in the SDQ nets in order?can we design the data section in ddr memories as we wish? just swap nets with each other?if this is true, i have no justification for it😟 grrmachine , 06-14-2020, 03:59 PM Hi @kazemiy974 Apr 2, 2015 · Options DDR3 - Swapping data lines + IMX6Q 03-31-201508:23 PM 1,844 Views stevenshi Contributor I Apr 23, 2015 · Hello sir Thanks for your reply as well as the links you have shared to me It was very useful. Jun 22, 2023 · Hi, We design a custom i. " What this means is that pin numbers can be swapped between Zynq and the SDRAM within a byte, or entire byte groups can be switched. Aug 3, 2023 · 3. 3. Do we connect DDR3 with out swapping data lines to Lately DDR3 is becoming more prevalent in new custom designs however I find that there isn’t much comprehensive document available for newcomers to the DDR franchise. DDR2, DDR3, DDR4, or LPDDR4 design and layout. g. In this article, we’ll delve into the world of RAM replacement, exploring the possibilities Apr 22, 2015 · Hello sir I had gone through the ddr3 guidlines by freescale I could'nt find any constrains on no of layers for routing. my problem is in DDR3 Configration. you might be able to swap pins on the fpga, depending which fpga you have, so say D8 comes out of another pin, but that has a set of second problems meeting timing . 7] lane). NXP application note “Hardware and Layout Design Considerations for DDR3 SDRAM Memory Interfaces” recommends ” Pin-swap within a given byte lane to optimize the data bus routes”. Note that the DQ signal cannot be swapped between data Dec 9, 2017 · You can swap the data lines freely within a byte. The only rule for DQ bit swapping on the TDA2x DDR2/DDR3 interface is that the DQ bits must be routed with their associated strobe (DQS) and mask (DM). for DDR#1, you have bits 0 and 1 in the upper byte and bit 2 in the lower byte. otherwise other file need to modify?? Apr 1, 2015 · Options DDR3 - Swapping data lines + IMX6Q 03-31-201508:23 PM 1,446 Views stevenshi Contributor I Apr 2, 2015 · Options DDR3 - Swapping data lines + IMX6Q 03-31-201508:23 PM 1,682 Views stevenshi Contributor I Hardware and Layout Design Considerations for DDR3 SDRAM Memory Interfaces This document provides general hardware and layout considerations and guidelines for hardware engineers implementing a DDR3 memory subsystem. If swapped, would settings need to be adjusted in Configtool, firmware, or MX7D_DDR3_register_programming_aid? 4. 1 (Swapping data lines) of the "Hardware Development Guidefor i. For Layout making for DDR3 there is Freescale application note AN3940 Hardware and Layout Design Considerations for DDR3 SDRAM Memory Interfaces You can find it on any Fr Apr 2, 2015 · OK, thank you for your support!thank you for your reply, can you kindly give me explain about "If byte lane swapping was done, target DDR IC register read value must be transposed according to the data line swapping". PDF (attached) We have swapped the same bits in the DQ15:8 byte as per the PDF but I can't find anything to tell me how to perform this swapping in the devicetree or otherwi DDR3L memories support bit swapping, a technique the designer can use to interchange data lines with one another, provided that they correspond to the same byte lane (e. 2) Bytes group can be swapped, all signals DQ, DQS, DM have to be swapped. Jan 29, 2017 · Hi All, In IMX6UL reference EVK design, DDR3 data lines are swapped in memory device side. example : Data 0 of PS controller pin connecting to Data 3 of Micron memory device Thanks & Regards Jones Jun 22, 2023 · We design a custom i. . So we are having 4 questions related to it. i am very puzzled. 0 Kudos Share Reply 1 Solution パラメータの詳細 : パラメータの詳細 例 : 例 1 : 次のように 1 列、9 バイトのデザイン (DDR3 インターフェイスの影部分で表示されているバンク) 1 列の例 最終的なパラメータは、次のように設定する必要があります。 Jul 24, 2014 · Hi Yuri, Thanks for the informative reply. I attached a image file it shows ddr3 schematic design,why aren't the names in the SDQ nets in order?can we design the data section in ddr memories as we wish? just swap nets with each other?if this is true, i have no justification for it😟 grrmachine , 06-14-2020, 03:59 PM Hi @kazemiy974 in section of ddr3 memory i found a new confusing issue and it is ddr3 data buses. How to map these bits to processor while initializing. data byte 1 from processor is connected to dql0 to Hi, We have a need for clarification that it is safe to ease layout routing by doing some swapping of signals *within* DDR3 data bus bytes? Background: Part Number: AM4376 currently, i'm using the AM4376 to develop my project. Basicaly no is a good answer. We have done DDR3 data line swapping for better routing. Apr 22, 2015 · Yes you can swap the pin outs of the data in controller within the byte. Q1. When swapping bits, keep all bits within the same byte group. Based on these bank selections, MIG generates a design with an ideal pin-out and design placement. Nov 13, 2024 · In a typical DDR3 data bus configuration, eight of these 10 I/Os are used for the DQ s, one is used for the data mask (DM), and one is left over for other signals in the memory interface. We are considering changing the DDR3L from two to one, based on the MCIMX7SABRE circuit. Embedded systems that use double data rate memory (DDR) realize increased performance over traditional single data rate (SDR) memories. So I want swapping these data pins. The following figure shows an example of the bit swapping technique which can be implemented in a SAMA5D2 board design Dec 4, 2020 · Hi, we are working with a custom board, that implemented data lines swapping, the note says target DDR IC register read value must be transposed according to the data line swapping. But can you replace DDR3 with DDR3L? Byte lane swapping on utilized lanes is allowed when you swap all the DQ/DQS/DM/DBI pins in the same byte lane with the other utilized byte lanes. 2 (available with ISE 13. But does this rule applicable for other SoC in general? メモリ インターフェイスおよび NOC Jul 17, 2024 · Part Number: AM5728 Tool/software: Hi Expert, Is it possible to SWAP on DDR3 data line? Customer has question about DDR3 data line swap of AM5728. On LPDDR2/LPDDR3, there is some constrains for Byte0 (no bit swap, no byte swap) as it is used to access internal registers. Jun 22, 2023 · DDR3 data pin swapping - How to configure DDR controller to determine the pins swapping? Auto-suggest helps you quickly narrow down your search results by suggesting possible matches as you type. can I swap the pin outs of the data in controller within the byte ,If swaping is done do I have to modify any thing in the software or straight away Hello, I have a question about Bit/Byte Swapping on DDR4 on the PS-Side. entire D [0:7] swap with entire D [8:15] b) It's understood that byte-to-byte swapping is usually allowable at FPGA controller (which consists of many banks). Jun 12, 2015 · I had gone through the ddr3 guidlines by freescale I could'nt find any constrains on no of layers for routing. each of the DDR3 have 16 bit data line. (i. Many DDR memories interface to high pin count FPGA like Xilinx or Altera, or DSP using T-Branch or Fly-By Route techniques. Feb 15, 2023 · The MIG 7 Series tool allows users to select specific Byte Groups within an FPGA Bank for Data and Address/Control groups. We don’t want to preclude being able to use DDR3 write leveling. You can swap the two bytes within the 16 bit bus (as long as you swap the DM pins to suit) . also your ucf file is pretty much useless without showing which chip is involved. DDR3 is a **** challenge to get working timmings if Mar 14, 2023 · Other Parts Discussed in Thread: SYSCONFIG Hi, I would like to confirm something about swapping DDR3 data lines on AM43xx. So the only possible way you could swap address bit 7 with an upper bit is if bit seven of Feb 11, 2021 · Do you know what a nibble in DDR memory design is? Jun 23, 2023 · We design a custom i. can I swap the pin outs of the data in controller within the byte ,If swaping is done do I have to modify any thing in the software or Mar 21, 2023 · Part Number: AM4377 Other Parts Discussed in Thread: AM4376 Hi all, Can ı DDR3 data pin or DDR3 address pin swap at their data pin or address pin groups ? For example; MT41K256M16TW-107 has been chosen. Jun 23, 2023 · For the byte and pin swapping, as I wrote, no software changes are to be made. Routing occurs in order by byte lane numbers, and data byte lanes are routed on the same layer. During the time when the data to the config registers is valid on the lower address lines, upper address lines should be low to conform to requirements for unused bits that are reserved for future use. Host D0 <--> DRAM DQU0 Host D8 <--> DRAM DQL0 The rest of pins are swapped within the byte lane. both ddr are 256 MB size. Oct 18, 2013 · To ease PCB routing between a TI 66AK2H12 and a DDR3 RAM device, is it acceptable to pin swap the data bits within a byte group, and to byte swap entire byte groups (DQ, DQS, DM) ? DDR SDRAM uses bidirectional single-ended data strobe (DQS); DDR3 and DDR4 SDRAM use bidirectional differential data strobes. The address pins are a different story, due to the burst/page-type interface. Where should I look to set this transpose value into the yocto configuration? Or how this transpose is configured Jun 14, 2020 · Hi @kazemiy974 As most of the DDR3 chips come in BGA packages and often it's tricky to route signals. The MIG tool should be used to generate a pinout for a 7 series DDR3 interface. " - this is needed for reading MR registers of ddr part. Where should I look to set this transpose value into the yocto configuration? Or how this transpose is configured? Solved! Go to Solution. 4. For ZU Feb 27, 2017 · Yes you can swap the DDR3 DQ pins on the processor (P1015) side within the byte lane. According to section 2. The best way to get help would be to show exactly which pins you swapped instead of expecting someone to find the swapped pins by looking at your ucf. May 23, 2021 · SDRAM swapping rules for bit and byte swapping are not usually described clearly for slow SDR memories. For DDR3 and DDR3L you can swap bits as much as you want within an eight bit byte. I attached a image file it shows ddr3 schematic design,why aren't the names in the SDQ nets in order?can we design the data section in ddr memories as we wish? just swap nets with each other?if this is true, i have no justification for it😟 grrmachine , 06-14-2020, 03:59 PM Hi @kazemiy974 MIG allows users to select banks for placement of Data, Address/Control, System Control, and System Clock. Also it is true that no software configuration changes are needed for DDR3, since all DDR register read data is across the address signals. 4. Now for better routing purpose, We have swapped the ddr data lines coming from the processor. DDR4 Pin Swapping Restrictions • Address/command/control bits cannot be swapped. 15) / (16. But what about Zynq Ultrascale\+ ? For some reason freescale DDR4 guide says that data lane bitswap for DDR4 is only allowed within a NIBBLE but not within a full bytelane. Information on Zynq UltraScale+ PS DDR pin swapping can be found in (UG1075) - Zynq UltraScale+ MPSoC Packaging and Pinouts Product Specification Note that additional pin swap restrictions are required if using the (infrequently used) Write CRC feature of DDR4. 31) at memory device side. I made a mistake on copying the reference design from the Zedboard on two DDR3 interface pins, DDR3-DM2 and DDR3-DM3 that are fixed on P1 and AA2 respectively on ZYNQ FPGA IO bank 502. But does this rule applicable for other SoC in general? What You Need to Know When Routing DDR3 Part 1 of 2 Is The Space What You Use Between PCB Tracks Wide Enough? (1H / 3H / 6H Crosstalk Simulation) Sep 8, 2023 · Author Topic: Mixing DDR3 data lines between bytes (Read 6018 times) 0 Members and 1 Guest are viewing this topic. MX6ULL board that connect to a DDR3 DRAM (x16) using data pin swapping. Jun 14, 2020 · Hi @kazemiy974 As most of the DDR3 chips come in BGA packages and often it's tricky to route signals. Byte groups (data and address/control) can be freely swapped with each other. The EVM Aug 3, 2023 · 4. I need to swap some pins for DDR constrain purpose. If your 4Gb SDRAM is a different size than the one in the Murata Yocto project you are referring to, then you need to adapt this in the device tree. If you want to change the timings or the impedance settings of the DDR, Nov 20, 2023 · We are using LPDDR2 and have wired the data bits as per the ST provided example STM32MP15XXAD_LPDDR2x16-Example-A01_Schematic. our HW engineers relayout the board for DDR3, the freeescale "Hareware development guide" had said that "Swapping data lines"(please check attachment_1). Do we need to do any additional changes for data line swapping Below is the schematics Solved! Go Apr 1, 2015 · hi Yuri Muhin: thank you for your reply, can you kindly give me explain about "If byte lane swapping was done, target DDR IC register read value must be transposed according to the data line swapping". A byte lane includes any signals associated with the aligned 8-bits of DQ, such as DM, DQS, DQS_N, DBI and DQ signals. See (Xilinx Oct 25, 2019 · This swaps are possible on DDR3/DDR3L as there is no memory register configuration using data lines (configuration uses address/command lanes). DDR3 Data, Mask and Strobe This DDR3 example is a 64-bit system and data is grouped into 8 subgroups (called byte lanes) Each byte lane consists of 8 parallel bidirectional bits and has its own mask bit and strobe. Does swapping of data pins with in byte lanes in the controller will create any issue in implemention parity algorithms in ECC ? This chapter provides the values that will always be used for the Zynq MPSoC PS Memory Controller with DDR3/3L, LPDDR3, DDR4 and LPDDR4 DRAM interfaces. Why DDR The first question you might ask is why to use DDR. I understand the following about swapping DDR3 data lanes, is that Mar 11, 2025 · Upgrading your computer’s RAM is one of the most effective ways to boost its performance, especially if you’re running multiple applications simultaneously or using resource-intensive software. The rules for swapping DQ byte lanes are as follows: You can only swap between utilized DQ lanes. The Virtex-6 FPGA Memory Solutions User Guide (UG406) states the following allowed changes for moving pins in the design generated by MIG: The address and control pin assignments can be in section of ddr3 memory i found a new confusing issue and it is ddr3 data buses. • DQ bits Jul 1, 2012 · This document defines the DDR3 SDRAM specification, including features, functionalities, AC and DC characteristics, packages, and ball/signal assignments. i found the SDB board has swap Jul 24, 2014 · 1. Best Dec 7, 2018 · When working with DDR3 and DDR4 routing, the fly-by topology begins with the controller, starts with Chip 0, and routes through Chip N—or the upper data bit. Where should I look to set this transpose value into the yocto configuration? Or how this transpose is configured? Jan 19, 2004 · Can I swap data lanes in the data bus of the DDR? I mean, can I, for example, connect DATA[0] from CPU to DATA[12] of DDR? it can help me in routing. Below is the pic. These 'stubs' seem to be matched length on the evaluation board. Feb 15, 2023 · MIG allows users to select banks for placement of Data, Address/Control, System Control, and System Clock. in section of ddr3 memory i found a new confusing issue and it is ddr3 data buses. but I don't know the exact principle which I can follow. Best regards igor Mar 23, 2015 · We swapped the DDR3 bits as recommended. that means I can swap Hi I am routing DDR3 on PCB that there are some conflicts on routing path. Dec 7, 2020 · Hi juanalbertogonz regarding " target DDR IC register read value must be transposed according to the data line swapping. All signals we Hi, Wish to seek advice for following concerns: a) Possible to swap pin at DDR3 chip side for entire byte lane? e. DDR3 is a **** challenge to get working timmings if Sep 23, 2021 · UG933 contains the following information: "Byte and bit swapping is allowed to facilitate PCB routing, except for LPDDR2, which specifically forbids swapping. This is very useful when trying to optimize a DDR layout routing. Differential DQS operation enables improved system timing due to reduced crosstalk and less simultaneous switching noise on the strobe output drivers Dec 7, 2020 · we are working with a custom board, that implemented data lines swapping, the note says target DDR IC register read value must be transposed according to the data line swapping. For lover byte, ı would like to swap DQ3-DQ1 and DQ0-6 ? Is it possible to swap for data group and address group? Like LikedUnlike muzaffer (Member) 9 years ago within byte data swapping is acceptable but address swapping is not. 1) How to configure the DDR controller so that it will read/write the data content correctly? Hi, Wish to seek advice for following concerns: a) Possible to swap pin at DDR3 chip side for entire byte lane? e. Initially, I had seen the post "AM4376: AM4376BZDND80" and thought that it should not swap about prime bits. Incompatible RAM can cause the system to malfunction, leading to data loss or corruption. any bits inside the D [0. Apr 23, 2015 · Hello sir I had gone through the ddr3 guidlines by freescale I could'nt find any constrains on no of layers for routing. 1) DQ signals can be swapped within a data byte. May 8, 2023 · Part Number: AM3359 In TMDSSK3358, all DQ bits in each of byte lanes are swapped for DDR3. 1) How to configure the DDR controller so that it will read/write the data content correctly? in section of ddr3 memory i found a new confusing issue and it is ddr3 data buses. Hi, I want to connect 7Z045 or 7Z100 zynq device DDR controller pins to MT41K256M16HA-125 DDR3 memory device PS (SOC) : shall i swap the data bits within the byte lane (0. Dec 4, 2020 · Hi, we are working with a custom board, that implemented data lines swapping, the note says target DDR IC register read value must be transposed according to the data line swapping. The following pin connections are good or not? Dec 19, 2023 · The least significant data bit is used for read / write leveling to automatically adjust the timing parameters for each byte. I used two chips DDR3L component . Hi Brett, yes you can do DQ swapping within a byte, or you can swap byte lanes. E. in hardware develop guide it seem to need change code. The purpose of this Specification is to define the minimum set of requirements for JEDEC compliant 512 Mb through 8 Gb for x4, x8, and x16 DDR3 SDRAM devices. Routing can be simplified by swapping data bits within a byte lane if needed. but your reply is not need change code. We are going to use 2 ddr3 through single chip select. Nov 15, 2022 · Note that when using 16-bits DDR3/DDR3L on a device supporting 32-bits, only DQ0-DQ15 should be used (i. 2. I have reading page 82 on Zynq UltraScale\+ Packaging and Pinouts page 82. So this may be ignored for DDR3(L). A byte lane includes any signals associated with the aligned 8-bits of DQ, such as DM, DQS, DQS_N, and DQ signals. xfvba yky1 mwj op ggpxo ldi zucqlj y4gj3 8u7 d5ne