F. Initialize
1、Check if the MCU is running program, and check if the system initialization passes after
power-on. If not, check if the peripheral circuit of the MCU is normal.
2、Make sure the MCU successfully resets the LT768x, that is, if the "System_Check_Temp"
function passes after reset. If not, check the interface and reset pin of the MCU and LT768x are
properly connected.
3、Make sure the MCU successfully initializes the LT768x. If there is any function does not pass
such as the “LT768_SDRAM_initail”function, try to reduce the communication speed of the
interface between the MCU and LT768x.
4、Check whether the MCU and the LT768 communicate normally through the Initialization
Function provided by the Levetop.
5、Use the Display-ON Function which provided by Levetop to enable the LCD output a normal
signal.
G.Display
1、If the above steps are normal, and the MCU program has controlled the LT768x output , such
as red, green, and blue, and if there is no picture is displayed, then first check whether the
LT768x LCD output signals PCLK, DE, HSYNC, and VSYNC have Waveform output. Make
sure the waveforms are correct (measured with an oscilloscope), and there signals are sent to
the FPC of the TFT panel. If there is no waveform, check if the chip has solder joints or replace
the chip.
2、If the LT768x's LCD output signals PCLK, DE, HSYNC, and VSYNC have no waveform output,
check if the “Display On”function was executed.
3、If the LT768x's LCD output signals PCLK, DE, HSYNC, and VSYNC has a waveform output,
check if the PCLK frequency matches the panel and if the HSYNC and VSYNC timings are
setting correctly (active high or active low) .
4、If the LT768x's LCD output signals are normal, check if the panel driver circuit voltage. And the
backlight circuit (LEDA+, LEDK-) voltage meets the panel requirements. If the voltage is not
match or no voltage, check and adjust the circuit.
5、If the panel has a Display ON/OFF control pin, double check whether the level of the secondary
pin meets the requirements. If it is not meet or low, check and adjust the circuit.
Figure 8：LT768x and TFT Driver Interface
