DS90UB941AS-Q1: The screen display is normal, but the i2c communication is abnorma

Part Number: DS90UB941AS-Q1

hardware link:soc-------ds90ub941--------ds90ub948------------lcd

register configuration:

    {0x01, 0x08},     //Disable DSI
    {0x11, 0x33},     //Disable DSI
    {0x5b, 0x10},     //select dsi pll colck
    {0x40, 0x04},     //Select DSI Port 0 digital registers
    {0x41, 0x20},     //Select DSI_CONFIG_0 register
    {0x42, 0x6f},     //Set DSI_SYNC_PULSES = 0
    {0x41, 0x21},     //Select DSI_CONFIG_1 register
    {0x42, 0x60},     //Set DSI_VS_POLARITY=DSI_HS_POLARITY=1
    {0x4f, 0x8c},     //Set DSI_CONTINUOUS_CLOCK, single DSI, 4 lanes, DSI Port 0 input
    {0x41, 0x30},     //Select DSI_HSW_CFG_HI register
    {0x42, 0x00},
    {0x41, 0x31},     //Select DSI_HSW_CFG_LO register 
    {0x42, 0x18},     //hsync-len = 12
    {0x41, 0x32},     //Select DSI_VSW_CFG_HI register
    {0x42, 0x00},
    {0x41, 0x33},     //Select DSI_VSW_CFG_LO register
    {0x42, 0x03},     //hsync-len = 3
    {0x40, 0x04},     //Select DSI Port 0 digital registers
    {0x41, 0x05},     //TSKIP_CNT set indirect addr (reg DPHY_SKIP_TIMING)
    {0x42, 0x2E},     //TSKIP_CNT set reg DPHY_SKIP_TIMING value
    {0x40, 0x10}, 
    {0x41, 0x86},
    {0x42, 0x0A},
    {0x41, 0x94},
    {0x42, 0x0A},
    {0x0e, 0x3f},     //TP_INT BL_EN
    {0x0f, 0x03},     //PWM     
    {0x10, 0x03},     //TP_RST NULL
    {0x01, 0x00}      //Enable DSI

Question 1:FREQ_DET_PLL

The difference between DSI clock and DSI PLL clock?

 Question 2:

The normal display indicates that the DSI clock is functioning properly. Why is there an abnormal i2c read-write operation

  • Hello,
    We have received your post and the investigation will take some time.
    Thanks for your patience.

  • 你好,

    感谢您的联系。让我来查看一下第一个问题。

    关于第二个问题:

    请提供更多关于异常 I2C 读写操作的详细信息?您是指无法与 941as 串行器通信吗?能否提供 SCL 和 SDA 波形以及可复现性统计数据?是否存在任何显示异常?

    BR,

    以斯帖

  • 1.941可以正常读写,但是无法读到948和tp
    读寄存器是未检测到电缆链路的状态,但是这种状态下显示是正常的,
    实车上没有办法获取波形
    2.显示开始是异常的,LINK_DETECT是0,应该是线路接触不良,我们有机质判断寄存器为1后会重新初始化948,现在出问题后948初始化成功,屏亮了,但是过一会儿又检测不到电缆链路,同时i2c读写tp失败,但是显示一直是正常的
  • Cable link not detected的情况下屏幕显示是正常的,但是i2c通信是异常的,无法读写948和tp

  • 你好,

    感谢您提供最新信息。请问有多少辆车出现这种情况?您能否更换FPD-Link连接线?

    能否使用上面提供的脚本,在出现问题时提供 941 寄存器的转储,并在工作状态下提供 941 和 948 寄存器的转储?

    BR,

    以斯帖