As per the standards, 4KB is the minm. AXI Master Read Transactions. "The write data interleaving depth is the number of different addresses that are currently pending in the slave interface for which write data can be supplied. but i saw AMBA 3. Secondly, the interconnect must ensure that. >or its possible with single-master cases also?. . AXI3 supports write interleaving. **BEST SOLUTION** Finally I solved. Write transaction ID on the GIF is verified for write ID consistency between the AXI and the GIF without write interleaving or out-of-order write responses. Requested operations will be split and aligned according. Allows reads to bypass writes, in contrast to axi_to_mem, however needs more hardware. In case if we have 2 burst transfers with A (awid=0,wlen=2), B(awid=1,wlen=2) at axi slave model, then the data can be sent as following. The AXI protocol is based on a point to point interconnect to avoid bus sharing and therefore allow higher bandwidth and lower latency. View AXI Notes. This book is for AMBA AXI Protocol Specification. wdata { Write data, actual data to be written. If the transmission unit is a block or packet. AXI4 does NOT support write interleaving. v : AXI central DMA engine rtl/axi_cdma_desc_mux. Transaction address will be randomly selected based on system address map. 1>读乱序的例子展示的是transaction粒度的乱序，读交织进一步允许transfer粒度的乱序。. However, since L2CC masterFree essays, homework help, flashcards, research papers, book reports, term papers, history, science, politicsStage 1: Read Calibration Part One—DQS Enable Calibration and DQ/DQS Centering 1. AXI Architecture for Write • A write data channel to transfer data from the master to the slave. Newest. 3. Activity points. Acceptance capability of data interleaving depth is retrieved data phase where the transfers. 1A is a view illustrating a process of interleaving the data transmitted by plural AXI masters and transmitting the interleaved data to an AXI slave 30 having interleaving acceptance capability of “2”. pdf". AXI BRAM. When address phases of READ and WRITE transactions get completed at same time, it is not deterministic whether it is a read-write or write-read scenario. AXI4 supports QoS, AXI3 does NOT suppor QoS. With Lack Santa And Jim Shore. Xilinx Linux PL PCIe Root Port. Interleaving is a process or methodology to make a system more efficient, fast and reliable by arranging data in a noncontiguous manner. The Comparator will check out-of-order transactions if it treats them symmetrically, with no constraint on which output, Reference or DUT, arrives first. Address register – It contains the address to specify the desired location in memory. Note I havenot generated testbench for the my write channel or read channel as there are a lot of signals involved. If you are not happy with the use of these cookies, please review our Cookie Policy to learn how they can be disabled. Write interleaving is hardly used by regular masters but can be used by fabrics that. 3. All rights reserved. then the BFM attempts to perform write data interleaving. 12. By continuing to use our site, you consent to our cookies. 19 March 2004 B Non-Confidential First release of AXI specification v1. The key features of the AXI protocol are: • separate address/control and data phases. Thanks a lot!!! Transaction ID信号，使AXI4协议可以完成自身的乱序机制，从AXI3到AXI4的进化中，write interleaving被取消了，大的方向下，AXI遵循着相同ID顺序执行，不同ID乱序执行的原则，同时从主设备-互联网络-从设备的连接中，Transaction ID可能会出现额外的位扩展. Verification IP (VIP) supports all four types of atomic transactions:. All five transaction channels use the same VALID/READY handshake process i want to do random write transcation, and here is the waveform, does this waveform meets AXI spec. One major up-dation seen in AXI4 is that, it includes information on the use of. 1A, the data transmitted by the AXI masters through an NoC router are transferred to an AXI slave 30 through an NI 20. Sector interleave size of interleaving in axi ip, link copied to apb bus at the read. This is to simplify the address decoding in the interconnect. This site uses cookies to store information on your computer. Multiple Intellectual Property (IPs) are integrated in a single SoC and these IPs communicate with the help of various bus protocols. 1A is a view illustrating a process of interleaving the data transmitted by plural AXI masters and transmitting the interleaved data to an AXI slave 30 having interleaving acceptance capability of “2”. AXI4 does NOT support writers intersect. This approach makes good use of memory. 6,828. sv. The AXI4 Cross-bar interconnect is used to connect one or more AXI4 compliant master devices to one or more AXI4 compliant slave devices. 1) March 7, 2011. I'm studying about AMBA 3. However, a master interface can interleave write data with different WID values if the slave interface has a write data interleaving depth greater than one. TheReaction score. Introduction. When 256 bits data is chosen in the GUI, this bus should be left undriven. Since AXI has 5 parallel channels running, many wires are used to lay the layout. Scenario 1: There. Separate read, write and snoop channelsThe write operation process starts when the master sends an address and control information on the write address channel as shown in fig. p. The user logic should provide a valid write address in the. However, the word of the data interleaving is not included in. "The write data interleaving depth is the number of different addresses that are currently pending in the slave interface for which write data can be supplied. >or its possible with single-master cases also? Yes. Activity points. point to point) scheme. This DUT consisted of default AXI-stream signals to communicate to and fro. AXI4 supports QoS, AXI3 does NOT suppor QoS. CoreAXI4Interconnect is a configurable core with the following features: • Supports high-bandwidth and low-latency designs. Note: The AXI Interconnect core is intended forWrite interleaving; this feature was retracted by AXI4 protocol. Appendix B Revisions1] AXI is a multi-channel bus with 5 independent channels like Write address channel, Read address channel, Write data channel, Read data channel, Write response channel (Read Response is sent. the write address channel and the write data channels of AXI are originally decoupled. A company shall be a Subsidiary only for the period during which such control Subject to the provisions of Clauses 2, 3 and 4, ARM hereby grants to LICENSEE a perpetual, non-exclusive, non-transferable, royalty free, worldwide licence to:(i) use and copy the relevant AMBA Specification for the purpose of developing and having developed products. I'm research info AMBA 3. Can anybody help me to understand the reasoning behind write data interleaving ordering restriction imposed by AXI spec. But it's not the only possible source of interleaved write data. Interleaved DMA: Interleaved DMA are those DMA that read from one memory address and write from another memory address. 5 Write data interleaving] "The order in which a slave receives the first data item of each transaction must be the same as the order in which it receives the addresses for the transactions. Parametrizable AXI burst length. Enables sharing the PCIe AXI DMA module between multiple request sources, interleaving requests and distributing responses. AXI specification says that the write data interleaving depth is statically configured and the slave declares a write data interleaving depth. You cannot interleave transactions using the same ID, so the data transfer IDs are the link to the preceding address transfer IDs, telling the destination of the transfer which transaction they are for. 3. One major up-dation seen in AXI is that, it includes information on the use of default signaling and • AXI Clock Converter connects one AXI memory-mapped master to one AXI memory-mapped slave operating in a different clock domain. The. Memory Interleaving is less or More an Abstraction technique. Gaming, Graphics, and VR. Submission Search. 1) April 24, 2012 Chapter 3: AXI Feature Adoption in Xilinx FPGAs Lock / Exclusive Access No support for locked transfers. By disabling cookies, some features of the site will not workWrite interleaving with Multi-AXI master Hi, I have multiple questions related to multi-master AXI4 system. AXI_ERRM_WDATA_ORDER The order in which addresses and the first write data Write data interleaving on Page 8-6 item are produced must match. It is a Technique that divides memory into a number of modules such that Successive words in the address space are placed in the Different modules. Documentation and usage examples. The AMBA AXI4 Interconnect core connects one or more AXI memory-mapped master devices to one or more memory-mapped slave devices. How can the master provide the write data for the two outstanding write addresses if these are write burst of burst length 5?There is one write strobe bit for every eight bits of write data. Chapter 4 Transfer Interleaving and Ordering Read this for a description of the stream interleaving and ordering restrictions. 1 Introduction. As shown in FIG. The AXI VIP provides example test benches and tests that demonstrate the. Hi, I'm a graduate student living in south Korea. Interleaving allows you to send WID transfers for a number of outstanding AW transfers, BUT. RESPONSE_TIMEOUT. While AXI 4 only supports read data interleave. In the past when writing to DDR ram that is connected to the PS, I have used Xilinx AXI DMA to DMA data into the PS. In Section III, we introduce the idea of interleaving and construct a simple interleaved scheme based on antenna selection. The bandwidth is measured as (number of bytes transferred in an interval)/ (latency). Adds test_i port for DFT. As shown in FIG. Firstly, I took DUT for testing purposes which is a UART module with AXI-Stream user interface. axi_ram_wr_rd_if module. 19 March 2004 B Non-Confidential First release of AXI specification v1. There is also an CXL 2. If you are not happy with the use of these cookies, please review our Cookie Policy to learn how they can be disabled. Finally the write response is sent from the Slave to the Master on. 是否支持乱序只与slave有关，与master无关。. axi_extra_0_0_wuser_data: 32: Input: Extra Write Data (AXI WUSER port). Pipelined AXI driver; back to back transfers with 0 in-between wait clocks. • support for unaligned data transfers, using byte strobes. Wrapper for pcie_us_axi_dma_rd and. As a result, AXI4 removed support for write data interleaving, which then removed the need for the WID signal (it was only needed to work out which outstanding write transaction the data related to). I have seen many IP providers e. 1) I would like to know how read and write address requests issued to slave are associated with read or write data. A single instance of the AXI NoC IP can be configured to include one, two, or four instances of the integrated MC. Write Data Interleaving in AXI. No. Introduction. Tx Control AXI4-Stream Rx Status AXI4-Stream Tx Payload AXI4-Stream Rx Payload AXI DDRx AXI4 AXI4 Read DataMover AXI4 Write AXI BRAM Interrupt Out (To AXI Intc) Interrupt Out. • uses burst-based transactions with only the start address issued. Trophy points. pcie_us_axi_dma module. EGO has seen many IP providers e. I have a few fundamental questions related to AXI-4 and I would appreciate if anyone can answer these. By disabling cookies, some features of the site will. AXI-4 questions. v. SIZE 2. 0 AXI. Checks all snoop transactions are ordered. AXI3 supports write interleaving. Burst Transfer AXI burst read operation ：The master only needs to send the start address of the burst, the slave will automatically calculate the address according to the burst start address and the burst site, and send the corresponding data and response to the master side. The data widths supported are: 32, 64, 128, 256, 512 and 1024. To extend the read interleave question & assuming this use case only valid in AXI interconnect. 2. Polymorphic interface; params_pkg. txt) or read online for free. Following is my write channel code : // // File name: axi_mcb_w_channel. AXI4 supports QoS, AXI3 does NONE suppor QoS. Also s_axi_awqos, s_axi_arqos, m_axi_awqos, m_axi_arqos are present, which should not be the case for AXI3, as. AXI Interconnect v2. Scholar, Embedded System and VLSI Design. I'm learn about AMBA 3. svt_axi_checker:: snoop_transaction_order_check. 9. AXI3中支持写交. Viewed 593 times. {"payload":{"allShortcutsEnabled":false,"fileTree":{"AXI_Protocol/Design and Verification":{"items":[{"name":"AXI_Interface. A single instance of the AXI NoC IP can be configured to include one, two, or four instances of the integrated MC. 2. WID is needed to support write data interleaving described in AXI3, but this isn't supported in AXI4, so no requirement to have a WID signal. Typically, the read-modify-write operation can be achieved with a single atomic operation. The testbench file is cdma_tb. This core provides…19 March 2004 B Non-Confidential First release of AXI specification v1. There is no write data interleaving in AXI4. The problem I am facing is in AXI interface of MIG where 4-bit ID signal is present for all the transactiHowever, a master interface can interleave write data with different WID values if the slave interface has a write data interleaving depth greater than one. >In AXI4 multi-master case how/where can i control 2 masters which are trying to access a single slave? First of all, an AXI4 master must not issue interleaved write data. Write Data Interleaving in AXI3 Slaves: With Write Data Interleaving, an AXI3 slave can accept interleaved write-data with different AWID values. 2 states, if you have an AXI3 legacy deisgn which needs a WID. 2. AXI read and write data channels by introducing. The Advanced eXtensible Interface (AXI), part of the ARM Advanced Microcontroller Bus Architecture 3 (AXI3) and 4 (AXI4) specifications, is a parallel high-performance, synchronous, high-frequency, multi-master, multi-slave communication interface, mainly designed for on-chip communication. Check description: Trace tag value on data channel or resposne channel should be valid as per the trace tag. AXI Upsizer. Secondly, the interconnect must ensure that. FIG. AXI BFM. AXI Slave Write Transactions. •. Check description: Trace tag value on data channel or resposne channel should be valid as per the trace tag. 0 SerDes PHY, it comprises a complete CXL 2. '}, readReorderingDepth: {type:. recently, i read "AMBA® AXI Protocol. Activity points. 7. An AXI master can provide two write addresses one after another if there is support of two outstanding addresses. - Read data of transactions with different ARID values can be interleaved. When. when the WID is present in the old AXI version, a WDATA re-order mechanism will be inferred, and thanks to the remove of WID, we do not need that mechanism any longer. 0 03 March 2010 C Non-Confidential First release of AXI specification v2. allavi. This supports reading and writing a. AXI burst write operation middle,You only need to send the start address of. AXI4 does NAY support write interleaving 3. Altera Mentor Verification IP Altera Edition AMBA AXI3/4TM User Manual • Axi3 bfm write data interleaving, Bfm read data interleaving, Supported simulators • Altera Measuring instruments Manuals Directory ManualsDir. >In AXI4 multi-master case how/where can i control 2 masters which are trying to access a single slave? First of all, an AXI4 master must not issue interleaved write data. scala . ° Configurable Write and Read transaction acceptance limits for each connected master. 4. This doesn't cover the case of simultaneous Read and Write commands, which is certainly possible for AXI. Following is my write channel code : // // File name: axi_mcb_w_channel. WID is removed in AXI4, so WDATA must strictly follow the AW order. {"payload":{"allShortcutsEnabled":false,"fileTree":{"drivers/dma":{"items":[{"name":"bestcomm","path":"drivers/dma/bestcomm","contentType":"directory"},{"name":"dw. can simplify the logic used, by not needing to do checks for 4K boundaries on the AXI-Write. In AXI Interconnect IP configuration, I changed the Acceptance parameter to 5 from 1 (All sides : Master Read/Write, Slave Read/Write). Synopsys NOT. What is the difference between burst and beat? A ‘beat’ is an individual data transfer within an AXI burst. Include the AXI Performance Monitor IPs which will display read/write latency and bandwidth. Data interleaving, however, is not supported. {"payload":{"allShortcutsEnabled":false,"fileTree":{"src":{"items":[{"name":"axi_atop_filter. The key features of the AXI protocol are: • separate address/control and data phases. The higher bits can be used to obtain data from the module. 1A, the data transmitted by the AXI masters through an NoC router are transferred to an AXI slave 30 through an NI 20. g. You can also instantiate the AXI Data Width Converter core directly in your design (without AXI Interconnect core) along any pathway between a wide AXI master device and a narrower AXI slave. Parametrizable interface width and. Carries additional write data when AXI Data Width of 288-bits data is selected in the HBM2 IP GUI. 2 states, if you have an AXI3 legacy deisgn which needs a WID. I think data interleaving should not be done within a single burst. pcie_axi_dma_desc_mux module. Let’s call the two queues ref_q for Reference transactions and dut_q for DUT transactions. In a write transaction, the slave uses the write response channel to signal the completion of the transfer to the master. Found this statement: "For a slave that supports write data interleaving, the order in which it receives the first data item of each transaction must be the same as the order in which it receives the addresses for the transactions. Integrated Memory Controller . axi_to_mem_interleaved and axi_to_mem_split properly instantiates a demultiplexer now. We could not find that page in version E or the latest version, so we have taken you to the first page of version E of AMBA AXI Protocol Specification. • separate read and write data channels, that can provide low-cost Direct Memory Access (DMA)The purpose of this page is to describe the the Xilinx Framebuffer Write / Read DMA driver. // Documentation Portal . Features of AXI 5 Channels (Write address, Write data, Write Response, Read data/response, Read address ) No strict timing relationship between address and data signal On chip, Point to Point Communication protocol Multiple Outstanding(Multiple request) Burst based transactions with only start address issued Aligned and non-aligned address support Out of order Data interleaving Atomicity. recently, i read "AMBA® AXI Protocol. AXI BFM. WDATA [ (8n)+7: (8n)]. Write interleave depth is a characteristic of the slave or the slave interface, rather than the master. By continuing to use our site, you consent to our cookies. If you are not happy with the use of these cookies, please review our Cookie Policy to learn how they can be disabled. Integrated Memory Controller . AXI is basically a multi-layer (i. CT-macros allowing to instantiate AXI structs with custom channel type names. The higher bits can be used to obtain data from the module. Good Morning, I am working on a ZU6EG Zynq ultrascale+ project for my company with a team of engineers. Thank you. The WSTRB [n:0] signals when HIGH, specify the byte lanes of the data bus that contain valid information. There are 3 types of AXI4-Interfaces (AMBA 4. 4. the data interleaving is responsible for slaves and the write data interleaving is responsible for masters. You say just an out-of-order responses by the interleaving. Tune for performance and re-simulate: Ensure that you have the right number of NoC NMUs and DDRMCs to meet your requirements. AXI Reference Guide UG761 (v13. Checks all snoop transactions are ordered. By working with the master and slave devices, the AXI protocol works across five addresses that include read and write address, read and. 42 AXI Reference Guide UG761 (v14. •. [AXI spec - Chapter 8. Read Data Interleaving is supported in AXI4 and following is my understanding on Data Interleaving: Multiple Read commands can be executed simultaneously and data interleaving is supported as long as all condition for ordering are followed. AMBA. 2. 4. This paper presents a work aimed to design the AMBA AXI4 protocol modeled in Verilog hardware description language (HDL) and simulation results for read and write operation of data and address are. 1. AXI RAM read/write interface with parametrizable data and address interface widths. If you are not happy with the use of these cookies, please review our Cookie Policy to learn how they can be disabled. Thank you for your feedback. svt_err_check_stats attribute. "For a slave that supports write data interleaving, the order that it receives the first data item of eachWrite-Write-Write-Write or Write-Read-Write-Read, etc. 8. Carries additional write data when AXI Data Width of 288-bits data is selected in the HBM2 IP GUI. PCIe AXI DMA module for Xilinx Ultrascale series FPGAs. Still, if multiple transactions are issued to Slave input of AXI interconnect, it is not accepting. Thank you. • The AXI SmartConnect core does not support discontinued AXI3 features: ° Atomic locked transactions: This feature was retracted by the AXI4 protocol. PCIe AXI master module. AXI3 supports write interleaving. find likely ancestor, descendant, or conflicting patches for. 3. [AXI spec - Chapter 8. In the past when writing to DDR ram that is connected to the PS, I have used Xilinx AXI DMA to DMA data into the PS. By continuing to use our site, you consent to our cookies. Address register – It contains the address to specify the desired location in memory. Most AXI3 masters do not support write interleaving. If two or four instances of the MC are selected, they are configured to form a single interleaved memory. io and either CPI or AXI for CXL. インターリーブまたはインターリービング（英: Interleaving）は計算機科学と電気通信において、データを何らかの領域（空間、時間、周波数など）で不連続な形で配置し、性能を向上させる技法を指す。Multiple streams of data can be transferred (even with interleaving) across a master and slave. Short burst of or alternating read/write data. ridge. 0 AXI out-of order - WID & RID - Architectures and Processors forum - Support forums - Arm Community - AXI terminology - Multiple outstanding , out of order , interleavingSi and then interconnect to data interleaving in axi protocol violation to generate the palladium xp runs in?. Condition to axi protocol burst write data lines and understand the response. An audio stream could also be connected to the AVI Mux filter, in which case the mux would interleave the two streams. ° Write interleaving: This feature was retracted by AXI4 protocol. Interleaving Options Non-interleaved Bank Interleave Without Chip Select Interleave Bank Interleave with Chip Select Interleave 12. 5. AXI3 carries locked transfers, AXI4 does NON support locked transfers. when the WID is present in the old AXI version, a WDATA re-order mechanism will be inferred, and thanks to the remove of WID, we do not need that mechanism any longer. By continuing to use our site, you consent to our cookies. 5. The user logic should provide a valid write address in the AWADDR bus and assert the AWVALID to indicate that the address is valid. The AMBA AXI protocol supports high-performance, high-frequency system designs. WID signal is not supported in AXI4. 17. . sequence_length 1. 4. For example, a slave with a write data interleaving depth of two that has four different addresses, all with different AWID values, pending can accept data for either of the first. This paper presents a work aimed to design the AMBA AXI4 protocol modeled in Verilog hardware description language (HDL) and simulation results for read and write operation of data and address are. ) IF a transaction is bufferable It is acceptable for a bridge or system level cache to provide write response. I change the hardware in EDK and then run the memory writing code in SDK and check if the data I write is being written to memory with delay or not. AXI read and write data channels by introducing. From the AMBA AXI4-Stream specification , the TDEST signal can be used to route AXI4 data stream. Hold Off Refresh for Read/Write: This allows the controller to delay a refresh to permit operations to complete first. +1 Colin Campbell over 4 years ago. 0 03 June 2011 D-2c Non-Confidential Public beta draft of AMBA AXI and ACE Protocol Specification 28 October 2011 D Non-Confidential First release of AMBA AXI and ACE Protocol Specificationawait axi_master. Figure 2-19: AXI Reference Guide UG761 (v13. When address phases of READ and WRITE transactions get completed at same time, it is not deterministic whether it is a read-write or write-read scenario. AXI3 supports locked transfers, AXI4 does NOT support locked transfers. 4 Normal write ordering. scala . #- Configure the AXI3 Slave VIP to interleaving depth of 1 #- Check that the Interconnect is forwarding the transactions to the AXI3 Slave VIP without write data interleaving. 6. 1 in the current AXI protocol spec for details of this. It addresses high-bandwidth, high-clock-frequency system designs and includes features that make it suitable for high-speed interconnect, typical in mobile and consumer applications. AXI3: Write data interleaving (for different IDs) is supported. Azad Mishra Tracking. One major up-dation seen in AXI is that, it includes information on the use of default signaling andAXI Interconnect v2. The objectives of the latest generation AMBA interface are to: be suitable for high-bandwidth and low-latency designs. • AXI4 Quality of Service (QoS) signals do not influence arbitration priority in AXI Crossbar. 3:17 AM AMBA. AXI 3 supports both read/write data interleave. Stage 4: Read Calibration Part Two—Read Latency Minimization 1. By continuing to use our site, you consent to our cookies. The various AXI channels operate mostly independently of each other, so there is no requirement that a master wait for the B channel response to one write transaction before starting a new AW or W channel transfer. Develop and analyze applications with graphics and gaming tools, guides, and training for games developers. 1 in the current AXI protocol spec for details of this. >Is it used only when we have multi-master cases? No. In the last article, we introduced AXI, the Advanced Extensible Interface, part of the ARM AMBA specification for SoC design. • separate read and write data channels, that can provide low-cost Direct Memory Access (DMA)Data Interleaving: In a multi master interconnect, lets consider master A initiated the transfer with a burst of 4 and master B with a burst of 2 then it follows as A1 B1 A2 B2 A3 A4 it means A started the transaction, then went to B because of idle cycle by A and again A likewise. Synopsys NO supporting write interlock in AXI3. 1 PG059 April 5, 2017 89 Chapter 3: Designing with the Core AXI Downsizer The Width Conversion core performs a downsizer function whenever the data width on the SI side is wider than that on the MI side. -Joe G. I have seen many IP providers e. You may reply publicly to this message via plain. Implement build_phase and create a TLM analysis export instance. "For a slave that supports write data interleaving, the order that it receives the first data item of each Write-Write-Write-Write or Write-Read-Write-Read, etc. In case if we have 2 burst transfers with A (awid=0,wlen=2), B(awid=1,wlen=2) at axi slave model, then the data can be sent as following. 1. With the Rambus CXL 2. The System-On-Chip (SoC) designs are becoming more complex nowadays. AXI3 supports write interleaving. Synopsys supporting burst lengths up to 256 beats in AXI3 IODIN take also seen many. Hi I am using Vivado 2017. 4 Standards Compliance The DW_axi_gs conforms to the AMBA 3 AXI and AMBA 4 AXI specifications defined in the AMBA AXI and ACE Protocol Specification from ARM. Interleaved DMA: Interleaved DMA are those DMA that read from one memory address and write from another memory address. Documentation and usage examples. However most applications tended to buffer up the write data at the master and then pass it in consecutive transfer cycles, rather than try to interleave. Select the checkbox for S AXI HP0 interface and for S AXI HP2 interface. phy b. axi_extra_0_0_wuser_data: 32: Input: Extra Write Data (AXI WUSER port). 5 Write data interleaving] "The order in which a slave receives the first data item of each transaction. AXI3 supports disable bank, AXI4 does NOT support locked transfers 4. mem_rdata_i: input mem_data_t [NumBanks-1:0] Memory stream. request regardless if the request was a write or a read. sv","contentType":"file"},{"name":"axi. 17. I think there would not be big advantages.