Custom our board based on AM335x starter kit

Hi,

The Beaglebone Black has an eMMC. Design files can be found here: http://elinux.org/Beagleboard:BeagleBoneBlack#Hardware_Files

Uh..., and which interface i can use, MMC? GPMC..etc?? do you mind please give me the answer of question 1 on the first post??

If your sysboot has USB or UART boot in the boot order, you should be able to use either USB or UART to program the eMMC. USB would be RNDIS while UART uses xmodem.

Steve K.

For example, if my board based on AM335x starter kit and it is a new one is produced in the factory, there is no any MLO, u-boot on it and it also have no SD Card slot(we prefer this design), do i have any other method to program eMMC and let it boot from eMMC??Because we have other products that can be program through Jtag, but AM335x stater kit doesn't have this interface.

Thank you: ). I will see that.

Hi:

       I know where the MLO(SPL) can be found is according to the sys_boot[] pin and i saw there are some resisters on the sys_boot[], thus the am335x starter kit will boot from SD card. My question is if I want to use other boot method, should i have some dip switches replace of the existing resistor on the sys_boot[] pin for my own usage??

Yes, you can place DIP switches to connect/disconnect the necessary Sysboot resistors.

Hi:

        I check a file named "BBB_SRM.pdf" from the link you provided as http://elinux.org/Beagleboard:BeagleBoneBlack#Hardware_Files, and at page 48 i saw the circuit design that will connect MMC1_DAT0~MMC1_DAT7 with eMMC pin, then i checkd the file named "TMDSSK3358_3H0009_REV1_2B_SCH.pdf", i found MMC_DAT4~MMCDAT7 was connecting to LEDs. Can i only connect MMC1_DAT0~MMC1_DAT3 to eMMC like original design??If yes, what is difference using that pins or not using that pins for eMMC usage, if no and i should use them for eMMC, do MMC1_DAT4~MMC1_DAT7 have a conflict to current GPIO usage??

Yes, the current Linux MMC driver supports only 4-bit mode, so you could connect only MMC1_DAT0...MMC1_DAT3 to eMMC. However future drivers could support the full 8-bit interface. My recommendation is to connect all 8 bits for future compatibility.

Hi, I found in the "TMDSSK3358_3H0009_REV1_2B_SCH.pdf" there are 3 different ZCZ package for AM3358, they are called "U26A", "U26B", "U26C", what is difference between them?? and which version i am using??

 "U26A", "U26B", "U26C" are schematic graphic parts. All three of them together make the ZCZ package.

Do MMC0 and MMC1 on the chip have different function?? because I saw spruh73k.pdf at 26.1.7.5.2, they have different restrictions.

These restrictions are valid only for booting from MMC0 and MMC1. Otherwise the MMC ports are identical.

Hi:

         I summarize some questions that make me still confused, it would cost a little time, but please help me answer these questions if u can.. Thank you.

(1)I saw the file named "TMDSSK3358_3H0009_REV1_2B_SCH.pdf", I found a pin named GPMC_AD0(GPIO1_0) connect to SDIO_D0 of WLAN module. Why not using MMC1_DAT0 in the mux to connect.

(2)I found GPIO1_0 and GPIO0_22 also can be configured as MMC1_DAT0, does it mean I have choice to select MMC1_DAT0 pin??

(3)What is the relation about GPMC and MMC??Because I never seen the pins are given as MMC_xxx, they always are treated as GPMC_xxx.

(4)There is connection in the AM335x starter kit using MMC1(WLAN), if I want to use eMMC, how do i connect these module??do they have a conflict??

(5)Do I need to build eMMC driver?? Or the rom code will initialize it just like SDCard?? if I need to build eMMC driver, how do I make the device could use it when it boot up??

(6)How to program eMMC?? And what is raw data and booting file, I found it will make different flow for rom code.

(7)How to change the register mux at booting up stage??

(8)What kind of the eMMC chip on the BeagleBoardBlack???

(1)I saw the file named "TMDSSK3358_3H0009_REV1_2B_SCH.pdf", I found a pin named GPMC_AD0(GPIO1_0) connect to SDIO_D0 of WLAN module. Why not using MMC1_DAT0 in the mux to connect.

You have to check the Linux source code and you will surely find that somewhere this pin is muxed to MMC1_DAT0. Moreover on the schematics the net name for this pin is exactly  MMC1_DAT0.

(2)I found GPIO1_0 and GPIO0_22 also can be configured as MMC1_DAT0, does it mean I have choice to select MMC1_DAT0 pin??

If you want to boot from MMC1 you need to use exactly the pins shown in Table 26-29 of the AM335X TRM Rev. K. Otherwise yes, a lot of functions can be muxed to more than one pin. You can use the pinmux tool to define the valid pinmux for your device (http://processors.wiki.ti.com/index.php/Pin_Mux_Utility_for_ARM_MPU_Processors ).

(3)What is the relation about GPMC and MMC??Because I never seen the pins are given as MMC_xxx, they always are treated as GPMC_xxx.

No relation. Only pinmuxing overlaps on some of the pins.

(4)There is connection in the AM335x starter kit using MMC1(WLAN), if I want to use eMMC, how do i connect these module??do they have a conflict??

You cannot connect both to the same MMC.

(5)Do I need to build eMMC driver?? Or the rom code will initialize it just like SDCard?? if I need to build eMMC driver, how do I make the device could use it when it boot up??

No need, Linux will take care of this.

(6)How to program eMMC?? And what is raw data and booting file, I found it will make different flow for rom code.

Normally eMMC that are available today just need to be partitioned and programmed just like an SD card.

(7)How to change the register mux at booting up stage??

Depending on the Linux SDK you use this is done either in the board file (SDK 6.0) or in the device tree (SDK 7.0)

(8)What kind of the eMMC chip on the BeagleBoardBlack???

2GB eMMC. Part number can be seen in the BBB BOM, available at http://elinux.org/Beagleboard:BeagleBoneBlack#Hardware_Files

From all your questions I gather that you are not very familiar with this processor and hardware design (no offence meant). I strongly suggest that before going to PCB layout you contact your local TI representative and request a schematic review of your design.

Hi:

           Thank you for your patient of answering my questions, i will consider your suggestions seriously. I have seen this file http://processors.wiki.ti.com/index.php/Pin_Mux_Utility_for_ARM_MPU_Processors  and I understood about 90% content, but in the end of this document, it only explain how to use on the  AM35x / AM37x / OMAP35x and my requirement is on the AM335x.....  And about programing eMMC, as I knew TI provided the script in the SDK named "create-sdcard.sh", the user only need to follow the command, the sd card would be programmed automatically... so I don't know how to use the method for sdcard that implement on eMMC. I found a TI wiki have explained it , but i don't sure this is work......,  http://processors.wiki.ti.com/index.php/Sitara_Linux_AM335x_Flash_Programming_Linux_Development 

About the pinmux files, you cannot use them directly in the AM335X Linux files, you can use them only as a template for the pinmux modifications that need to be made.

Regarding eMMC programming, Uniflash is one way of doing it, but it will only work if you have an available Ethernet or USB port to boot from. Another way is to boot to kernel login from an SD card and use fdisk to partition and format the eMMC. Required steps are given in this post: http://e2e.ti.com/support/arm/sitara_arm/f/791/p/363990/1279458.aspx#1279458

Hi:

       Where can i find these files(mux.h..etc)?? Let me clarify it again. First, I can use Pin Mux Utility to generate the pin file i want, next, I need to find the corresponding file and replace the definition inside from the file made by Pin Mux Utiltiy and finally rebuild the u-boot, am i right?

Yes, this is correct. I don't know which Linux version you are using. In SDK 6.0 the pinmux would be in the board file, and again in the kernel. In SDK 7.0 device trees are used.

I am using SDK7.0, what is device trees? Is there any document explain it. Sorry for my poor knowledge..

Sorry, I am not a Linux expert. These are DTS files I think. Check the documentation within the SDK.

That's fine, I will check that by myself, thank you. Can I change the pinmux when kernel is running?? Just like I can change the input or output of GPIO by GPIO Driver wrote by myself.

Yes, you just need to write the new value to the proper padconf register.

Hi, I am studying device tree, I found lots of similar name like "am335x-bonblack.dtb", "am335x-bone.dtb", "am335x-evm.dtb", "am335x-evm-profile1.dtb", "am335x-evmsk.dtb" in the /(SDK_PATH)/board-support/linux-3.12.10-ti2013.12.01/arch/arm/boot/dts/. Which one is the .dtb file made from dts that is called in booting process??

Hi, can u tell me this information pls, thank you. Or is it defined in u-boot source code?

Hi ;

          We want to consider the other supplier for touch screen, but their TFT LCD didn't have some pins like "XR", "YD", "XL", "YU"(pin 37~pin 40), I want to know what is the function for these pins(I only know they are connecting to ADC input of AM3358) and are they necessary for touch screen. We are considering this TFT LCD. http://www.winstar.com.tw/products_detail_ov.php?lang=en&ProID=372

These are the 4-wire touchscreen signals. Please contact your LCD manufacturer for information how the touchscreen signals come out on the LCD you have chosen.

Hi:

           Does AM335x have a limitation for the standard of eMMC ?? Or depend on which standard type of eMMC itself and the module mmc of AM335x could support all of them.

to have your post properly tracked, please do not add more questions to a post that was already answered and verified. Please start a new one.