README
1mx6memcal - a tool for calibrating DDR on i.MX6 boards.
2
3The mx6memcal board isn't a real board, but a tool for use in bring-up of
4new i.MX6 board designs.
5
6It provides a similar function to the tool from NXP([1]) with a number
7of advantages:
8
91. It's open-source, so it's easier to change if needed.
10 Typical reasons for needing to change include the use of alternate
11 UARTs and PMIC initialization.
122. It produces an image that's directly loadable with imx_usb [2] or
13 SB_LOADER.exe [3].
14 The NXP tool requires either a cumbersome JTAG connection that
15 makes running the DDR very slow or a working U-Boot image that
16 suffers from a chicken-and-egg problem (i.e. where do you get the
17 DDR parameters for U-Boot?).
183. It doesn't prompt for parameters, so it's much faster to gather
19 data from multiple boards.
204. Parameters to the calibration process can be chosen through
21 'make menuconfig'.
22
23When booted, the mx6memcal board will run the DDR calibration
24routines and display the result in a form suitable for cut and
25paste into struct mx6_mmdc_calibration. It can also optionally
26produce output in a form usable in a DCD-style .cfg file.
27
28Selections in Kconfig allow most system design settings to be chosen:
29
301. The UART number and pad configuration for the UART. Options
31 include support for the most frequent reference designs on
32 i.MX6DQ/SDL (SABRE Lite and SABRESD designs).
332. The memory bus width (64 and 32-bit)
343. The number of chip-selects in use
354. The type of DDR (DDR3 or LPDDR2). Note that LPDDR2 support
36 is incomplete as of this writing.
375. The type of DDR chips in use. This selection allows re-use of common
38 parts and four DDR3 and two LPDDR2 parts are currently defined
396. The On-die termination value for the DRAM lines
407. The DRAM drive strength
418. The RTT_NOM and RTT_WR termination settings
429. RALAT/WALAT latency values
43
44References:
45[1] - NXP DDR Stress Test Tool - https://community.nxp.com/docs/DOC-105652
46[2] - Boundary Devices imx_usb_loader
47 https://github.com/boundarydevices/imx_usb_loader
48[3] - Use of SB_Loader.exe
49 https://boundarydevices.com/windows-users-and-unbricking
50