Hitachi TX20D26 LCD support

    Hello,
    I'm trying to use new Hitachi LCD 800x480 display with NetDCU8.
    Display model is TX20D26VM0APA RGB with 40 pins interface.
    Datadsheet can be downloaded here:
    <!-- m --><a class="postlink" href="http://www.hitachi-displays-eu.com/doc/TX20D26VM0APA.pdf">http://www.hitachi-displays-eu.com/doc/ ... VM0APA.pdf</a><!-- m -->


    Is there any corresponding adapter from F&S for use it with NetDCU8 ?
    Can be connected to NetDCU8 with no problems (I see in datasheet that no Vsync and Hsync are used) ?
    what about RST signal of the LCD (pin 35) ? can be no connected?
    Which similar LCD script can I start from to make this model work?


    Thanks

    Hello,


    - sorry we have no adapter for this LDC.


    - NetDCU8 is designed for LCD up to VGA. Nevertheless the LCD may work when your application does not need a high frame rate. I would start using a driver like http://www.fs-net.de/download/lcd/netdcu8/TX18.txt. You will find a list of drivers here http://www.fs-net.de/cms/index.php?id=81.

    F&S Elektronik Systeme GmbH
    As this is an international forum, please try to post in English.
    Da dies ein internationales Forum ist, bitten wir darum, Beiträge möglichst in Englisch zu verfassen.

    Hello,
    Finally NetDCU8 works great with Hitachi display TX20D26VM0APA (touch integrated) or TX20D26VM0AAA (no touch).


    The config used if you want add to your database support is:


    reg open \drivers\display\Samsung
    reg create key mode100
    reg set value name string "Hitachi TX20D26"
    reg set value EFW dword 8
    reg set value BFW dword 4
    reg set value msignal dword 2
    reg set value rows dword 480
    reg set value LPP dword 480
    reg set value width dword 115
    reg set value height dword 86
    reg set value contrastenable dword 0
    reg set value contrastvalue dword 0
    reg set value type dword 6
    reg set value config dword 0x00700000
    reg set value columns dword 800
    reg set value PPL dword 800
    reg set value HSW dword 32
    reg set value bpp dword 16
    reg set value lcdclk dword 33000000
    reg set value VSW dword 2
    reg set value BLW dword 30
    reg set value ELW dword 16
    reg set value EnableCursor dword 1
    display mode set 100
    reg set value contrastValue dword 0x5ff



    Thanks

    Hello,
    thank you for update this thread with your tested data set.
    If you encounter performance problems you may decrease the clock to get better results:

    Code
    1. reg open \drivers\display\Samsung\mode100
    2. reg set value lcdclk dword 25000000
    3. reg save

    F&S Elektronik Systeme GmbH
    As this is an international forum, please try to post in English.
    Da dies ein internationales Forum ist, bitten wir darum, Beiträge möglichst in Englisch zu verfassen.

    Hello again,


    After sometime, I was testing different lcdclk frecuencies for NetDCU8 and this LCD, finally I use 16000000 with no problems.


    Now, we replace NetDCU8 with NetDCU10 with same Hitachi LCD, and I have detected that sometimes, winCE system does not start, and lines appears on the screen instead of win desktop...


    I have testes again with different lcdclk values for N10 and finally 30000000 seems to be ok.


    Is there any explication to these different lcdclk values in NetDCU8 and NetDCU10 with same LCD ?? (I know N10 is 25% faster theorically, but this is so important ?)


    Could be a valid config file for both boards or is not recommended due to perfomance issue ?

    Quote from "jopomo"

    After sometime, I was testing different lcdclk frecuencies for NetDCU8 and this LCD, finally I use 16000000 with no problems.


    16 MHz is a little too low for this display. The specification says 25 to 36 MHz.


    Quote

    Now, we replace NetDCU8 with NetDCU10 with same Hitachi LCD, and I have detected that sometimes, winCE system does not start, and lines appears on the screen instead of win desktop...


    I have testes again with different lcdclk values for N10 and finally 30000000 seems to be ok.


    This is perfect, as 33 MHz is the "typical" clock rate for this display.


    Quote

    Is there any explication to these different lcdclk values in NetDCU8 and NetDCU10 with same LCD ?? (I know N10 is 25% faster theorically, but this is so important ?)


    The problem is that on NetDCU8 and NetDCU10 the display clock can not be configured as flexible as we would like. The clock is always derived by dividing a base clock by an integer. And the base clock is different on these two boards. On the NetDCU8, it is 51 MHz, on the NetDCU10, it is 66 MHz. Therefore if you request 33 MHz for the display, this speed can be exactly achieved by dividing 66MHz by 2 on the NetDCU10. However on the NetDCU8, this is not possible. By dividing with 2, we get 25.5 MHz, and the next value is 51 MHz. I don't know how the driver computes the clock speed, but maybe it selects 51 MHz when you request 33 MHz. So changing this value to 25MHz on NetDCU8 should be sufficient to be in the range of the specification. Why you need to go down to 16 MHz is not evident to me. Maybe the driver has an additional "off-by-1" problem, sou you actually get 25.5MHz when requesting 16MHz. Maybe a newer kernel version will help here. For example there were changes in the LCD driver in V1.39, 080731.


    Maybe you can check with an oscilloscope the real frequency of the pixel clock.

    F&S Elektronik Systeme GmbH
    As this is an international forum, please try to post in English.
    Da dies ein internationales Forum ist, bitten wir darum, Beiträge möglichst in Englisch zu verfassen.