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Important: If you have any questions or would like to report any issues with the DDR tools or supporting documents please create a support ticket in the i.MX community. Please note that any private messages or direct emails are not monitored and will not receive a response. i.MX 6/7 Series Family DDR Tools Overview This page contains the latest releases for the i.MX 6/7 series DDR Tools. The tools described on this page cover the following i.MX 6/7 series SoCs: i.MX 6DQP (Dual/Quad Plus) i.MX 6DQ (Dual/Quad) i.MX 6DL/S (Dual Lite/Solo) i.MX 6SoloX i.MX 6SL i.MX 6SLL i.MX 6UL i.MX 6ULL/ULZ i.MX 7D/S i.MX 7ULP The purpose of the i.MX 6/7 series DDR Tools is to enable users to generate and test a custom DRAM initialization based on their device configuration (density, number of chip selects, etc.) and board layout (data bus bit swizzling, etc.). This process equips the user to then proceed with the bring-up of a boot loader and an OS. Once the OS is brought up, it is recommended to run an OS-based memory test (like Linux memtester) to further verify and test the DDR memory interface. The i.MX 6/7 series DDR Tools consist of: DDR Register Programming Aid (RPA) DDR Stress test _________________________________________________________ i.MX 6/7 Series DDR Stress Test The i.MX 6/7 Series DDR stress test tool is a Windows-based software tool that is used as a mechanism to verify that the DDR initialization is operational prior for use in u-boot and OS bring-up. The DDR Stress Test tool can be found here: i.MX 6/7 DDR Stress Test Tool Note that the DDR Stress test tool supports all of the above i.MX SoCs, however, some of the supported i.MX SoCs named in the tool support multiple i.MX SoCs as follows: MX6DQ – when selected, this supports both i.MX 6DQ and i.MX 6DQP (Plus) MX6DL – when selected, this supports both i.MX 6DL and i.MX 6S (i.MX 6DLS family) MX6ULL – when selected, this supports both i.MX 6ULL and i.MX6 ULZ MX7D – when selected, this supports both i.MX 7D and i.MX 7S _____________________________________________________________________________ i.MX 6/7 Series DDR Register Programming Aid (RPA) The i.MX 6/7 series DDR RPA (or simply RPA) is an Excel spreadsheet tool used to develop DDR initialization for a user’s specific DDR configuration (DDR device type, density, etc.). The RPA generates the DDR initialization script for use with the DDR Stress Test tool. For a history of the previous versions of an RPA, refer to the Revision History tab of the respective RPA. To obtain the latest RPAs, please refer to the following links: i.MX 6DQP i.MX6DQP Register Programming Aids i.MX 6DQ i.MX6DQ Register Programming Aids i.MX 6DL/S i.MX6DL Register Programming Aids i.MX 6SoloX i.MX6SX Register Programming Aids i.MX 6SL i.MX6SL Register Programming Aids  i.MX6SLL i.MX6SLL Register Programming Aids i.MX 6UL/ULL/ULZ i.MX6UL/ULL/ULZ DRAM Register Programming Aids i.MX7D i.MX7D DRAM Register Programming Aids i.MX 7ULP i.MX7ULP DRAM Register Programming Aids _____________________________________________________________________________ DRAM Register Programming Aids FAQ    
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  Question: How can we generate an ARM DS5 DStream format DDR initialization script using the DRAM Register Programming Aid?  Answer: Some RPAs include a  "DStream .ds file" tab for the ARM DS5 debugger specific commands. The i.MX6UL/ULL/ULZ DRAM Register Programming Aids for example already has this supported. However, the user can easily create  the .ds format from the existing .inc format. The basic steps to convert .inc files to .ds format are as follows: 1)  Replace the one instance of setmem /16 with mem set 2)  In that same line, replace 0x020bc000 = with 0x020bc000 16 3)  Use a Replace All command to change setmem /32 with mem set 4)  Use a Replace All command to change = with 32 5)  Use a Replace All command to change // with # 6)  Save as a .ds file.   Question: When using a 528MHz DRAM Controller interface with a DDR memory of a faster speed bin, which speed bin timing options should one use? Answer: For example, let’s assume our MX6DQ design is using a DDR3 memory from a DDR3-1600 speed bin.  However, the maximum speed of the MMDC interface for the MX6DQ using DDR3 is 528MHz.  Should we use the 1600 speed bin (800MHz clock speed) or the 1066 speed bin (533MHz clock speed)?  In short, the user should use the timings rated for the maximum speed (frequency) with which you are running, in this case DDR3-1066 (533MHz).  In some cases, like when using the MX6DL, the maximum DDR frequency is 400MHz.  In this case, you would want to try and use 800 timings found in the AC timing parameters table.  However, most DDR3 devices have speed bin tables that may go only as low as 1066, in which case you would use the closest speed bin to your operational frequency (i.e. the 1066 speed bin table).     Question: Some timing parameters may specify a min and max number, which should I use? Answer: In most cases, you will want to choose the minimum timings.  Some DRAM controllers may have a tRAS_MAX timing parameter, in which case you would obviously use the maximum tRAS parameter given in the DRAM data sheet. Also, for timing parameters tAONPD and tAOFPD, we also want to use the maximum values given in the DDR3 data sheet. These represent the maximum amount of time the DDR3 device takes to turn on or off the RTT (termination), therefore, we should wait at least this amount of time before issuing any commands or accesses.   Question: Some timing parameters state things like “Greater of 3CK or 7.5ns”; which should I use? Answer: This depends on your clock speed.  Say you are running at 533MHz.  At 533MHz, 7.5ns equates to 4CKs.  In this case, 7.5ns at 533MHz is GREATER than 3CK, so we would use the 7.5ns number, or 4CKs. At 400MHz, 7.5ns equates to 3CKs.  In this case, we’d simply use 3CKs.   Question: I have a design that will throttle the DDR frequency (dynamic frequency scaling).  At full speed, I plan to run at 533MHz, and then I plan to throttle down to say 400MHz whenever possible.  Do I need to re-calculate my 400 MHz timing parameters that were initially set for 533MHz? Answer: It is not necessary to re-calculate timing parameters for 400MHz, and you can re-use the ones for 533MHz.  The timings at 533 MHz are much tighter than 400 MHz, and the key here is to NOT violate timings.  Also, it may be a bit of a hassle maintaining two sets of timing parameters, especially if later in the design, you swap DDR vendors that might require you to re-calculate some timing parameters.  It’s easier to do it once and to come up with a combined worse-case timing parameters for 533MHz, which you know will work at 400MHz.  But, if you don’t mind maintaining two sets of timing parameters, and really want to optimize timings down to the last pico-second for 400MHz, then knock yourself out.   Question: Can I use these Register programming aids for both Fly by and T- Topology ? Answer Yes The DDR register programming aid is agnostic to the DDR layout. The same spreadsheet works for both topologies. We recommend running write leveling calibration for both topologies and the values returned by the Write Leveling routine from the Freescale DDR stress test should be incorporated back to the customer specific initialization script. The DDR stress test also has a feature whereby it evaluates the write leveling values returned from calibration and increments WALAT to 1 if the values exceed a defined limit. The DDR stress test informs the user when the Write Additional latency (WALAT) exceeds the limit and should be increased by 1, and reminds the user to add it back in the customer specific initialization script if required.   WALAT - 0 00000000 WALAT: Write Additional latency. Recommend to clear these bits. Proper board design should ensure that the DDR3 devices are placed close enough to the MMDC to ensure the skew between CLK and DQS is less than 1 cycle.     Question: Can I use the DEFAULT Register programming aid values for MDOR when using an Internal OSC instead of the recommended 32.768 KHZ XTAL ? Answer No, NXP recommends reprogramming these values based on the worse case frequency (Max clock) of the internal OSC of the device to guarantee JEDEC timings are met. Please refer to  Internal Oscillator Accuracy considerations for the i.MX 6 Series for more details  
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Recently, some customers are using i.MX processor, they want to add raid & LVM function support to the kernel, but they have encountered the problem that the compilation cannot pass. Tested it in L4.14.98, L4.19.35 & L5.4.x, Only L4.14.98 bsp exists the problem. Here are the experimental steps I have done, including the same problems I encountered with the customer, and how to modify the kernel to ensure that the compilation passes. 1. Exporting cross compilation tool chain from yocto BSP (1) Downloading Yocto BSP and compiling it. Following steps in i.MX_Yocto_Project_User's_Guide.pdf, download Yocto BSP and compile it successfully. (2) Exporting cross compilation tool chain Following methods described in i.MX_Linux_User's_Guide.pdf, export cross compilation tool chain from yocto BSP. See Chapter 4.5.12 of the document, please! Then cross compilation tool chain will be like below: (3) Copying linux BSP source code to a new directory # cd ~ # mkdir L4.14.98-2.0.0 # cd L4.14.98-2.0.0 # cp -r ~/imx-yocto-bsp/build-fb/tmp/work/imx6qsabresd-poky-linux-gnueabi/linux-imx/4.14.98- r0/git ./ Then all linux source code has been copied to L4.14.98-2.0.0, which is the top directory of linux kernel source code, I will compile kernel image here. 2. Compiling linux kernel # cd ~/L4.14.98-2.0.0 # source /opt/fsl-imx-fb/4.14-sumo/environment-setup-cortexa9hf-neon-poky-linux-gnueabi # export ARCH=arm # make imx_v7_defconfig # make menuconfig Then we will add RAID and LVM modules to linux kernel. In order to reproduce errors, I added all related modules to kernel. See below, please! Device drivers---->Multiple devices driver support (RAID and LVM) After save and exit, began to compile kernel. # make (make –j4) The following errors will occur: ------------------------------------------------------------------------------------------- drivers/md/dm-rq.c: In function ‘dm_old_init_request_queue’: drivers/md/dm-rq.c:716:2: error: implicit declaration of function ‘elv_register_queue’; did you mean ‘blk_register_queue’? [-Werror=implicit-function-declaration] elv_register_queue(md->queue); ^~~~~~~~~~~~~~~~~~ blk_register_queue cc1: some warnings being treated as errors scripts/Makefile.build:326: recipe for target 'drivers/md/dm-rq.o' failed make[2]: *** [drivers/md/dm-rq.o] Error 1 scripts/Makefile.build:585: recipe for target 'drivers/md' failed make[1]: *** [drivers/md] Error 2 Makefile:1039: recipe for target 'drivers' failed make: *** [drivers] Error 2 ------------------------------------------------------------------------------------------- 3. Finding out root cause and solving it (1) elv_register_queue( ) function The function is loaded in dm-rq.c : int dm_old_init_request_queue(struct mapped_device *md, struct dm_table *t) { … … elv_register_queue(md->queue); … … } BUT compiler didn’t find it’s declaration and entity. Searching source code, and found it declared in linux_top/block/blk.h: … … int elv_register_queue(struct request_queue *q); … … It’s entity is in linux_top/block/elevator.c: int elv_register_queue(struct request_queue *q) { … … } (2) Adding declaration and exporting the function --- Declaration Add the line below to dm-rq.c: … … extern int elv_register_queue(struct request_queue *q); … … --- Exporting the function(elevator.c) Add EXPORT_SYMBOL(elv_register_queue); to the end of function, see below. int elv_register_queue(struct request_queue *q) { … … } EXPORT_SYMBOL(elv_register_queue); 4. Re-compiling Linux Kernel The above error will not occur and the compilation will complete successfully.   NXP CAS team Weidong Sun
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