Method for testing liquid crystal display (LCD) controller by using frame synchronization signal control switch

Abstract

The invention provides a method for testing a liquid crystal display (LCD) controller by using a frame synchronization signal control switch. The method comprises the following steps of setting an LCD controller, a video input controller for acquiring data of the LCD controller and a multi-path switch; dividing a plurality of data pins of the LCD controller into multiple groups, and acquiring data signals transmitted by a group of data pins through data acquisition pins of the video input controller through the multi-path switch; respectively acquiring a line synchronization signal pin of the LCD controller or a data signal transmitted by an effective data enable pin by an HREF signal pin of the video input controller through a selection pin of a selection switch; cutting off connection between the line synchronization signal pin and the HREF signal pin when the enable pin of the selection switch acquires that a frame synchronization signal pin of the video input controller is in high level; and connecting the connection between the line synchronization signal pin and the HREF signal pin when the enable pin acquires the low level. The method has the advantage that data acquired by the video input controller can be stable.

Description

【Technical field】 [0001] The invention relates to the field of functional testing of an LCD controller, in particular to a method for testing an LCD controller by using a frame synchronization signal to control a switch. 【Background technique】 [0002] Currently, the LCDC is tested by testing the LCD controller (ie LCDC) and the video input controller (ie CIF) with each other. During the LCDC test process, because LCDC has two horizontal synchronization signal pins, DEN and HSYNC. In the actual application process of the product, these two signals may be used, so when testing, these two signals must be connected to the HREF signal pin (ie CIF_HREF) of the video input controller for testing to ensure that two Signals can be used normally. [0003] In the previous test plan, a switch was used to switch the two signals of DEN and HSYNC, and the enable pin (ie OEB) of the switch was controlled by a general-purpose IO port (ie GPIO). Although both DEN and HSYNC are horizontal ...

AI Technical Summary

Problems solved by technology

Even during one line, the DEN and HSYNC signals are the same, but in the same frame, the two signals are still different; during the invalid period of the frame synchronization signal (ie VSYNC) (see figure 1 ), the HSYNC signal still exists, while the DEN signal remains inactive

[0004] The existing test method uses GPIO to control the enable pin of the switch. When testing the HSYNC signal, the signal received by the HREF signal pin of the video input controller will have a signal during the invalid period of VSYNC (see figure 2 ), resulting in probabilistic errors in the data collected by the video input controller, affecting the stability of the test

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