With the improvement of information technology, people have higher and higher requirements for visual appreciation. "Visual impact" has become a standard for people to judge display performance. The visual impact not only requires the screen size to be very large, but the most important thing is that the screen display is clear, including pictures and text. In order to meet this demand, this article takes Jingwei Yage CME-M5 (Jinshan) as an example to analyze how to superimpose characters in the HDMI high-definition signal and finally achieve the process of high-definition output.
As shown in the figure below, it is not difficult to see that the HDMI high-definition signal is sent to the CME-M5 through the HDMI to RGB chip, and after being superimposed with the external character chip in high-definition, then sent to RGB through HDMI.
Putting aside other functions, verify from the simplest By-Pass, that is, 150MHz 24bit RGB in, without any processing, directly send 150MHz 24bit RGB out, if By-Pass can't get it, debug other functions Also in vain. The key codes of By-Pass are as follows:
The gray scale verification is the easiest to see the problem. Simply add, what is gray scale?
The gray scale represents the gradation level with different brightness from the darkest to the brightest. The more intermediate levels, the finer the picture effect that can be presented. Take 8bit panel as an example, it can express the 8th power of 2, which is equal to 256 brightness levels, we call it 256 gray scale.
Corresponding to digital logic, it is the process of R / G / B gradual change from 0 to 255, divided into 256 equal parts, with an increment of 1, called 256 gray levels; divided into 8 equal parts, with an increment value of 32, called 8 gray levels.
The fake design is a 256-level black-and-white gray screen, and the RGB three colors are changed from FF to 00 at the same time, that is, 24 data lines are simultaneously level-turned, which has the highest power supply and speed requirements for FPGA chips, so special test verification, Grayscale can basically verify whether the quality of video transmission is stable and reliable, and other things that pass pictures to pass are actually not counted.
Well, we will verify with 256 gray levels as a reference legend.
According to the general CPLD EPM240 design, the straight-through effect is perfect, no doubt, it has been widely used. The normal effect is as follows, no bright lines, no noise.
And the display effect through M5-ByPass is shown below (a few sample pictures), and gray lines of several colors appear bright lines.
Based on the above, the By-Pass method like CPLD does not work. There are generally two gray-scale bright line problems:
(1) One is insufficient drive current;
(2) The other is that the IO or clock speed cannot keep up, and the data is not aligned;
Starting with the first solution, the default HS, VS output 4mA (default) is changed to 8mA under primace 7.2, and the PCLK with faster flip speed is changed to 16mA. The input is all pulled up and weakly pulled up. After the change, only the yellow gray level is improved (the bright line is not visible), and the other is not changed.
Design specifications
Material body: ABS Surface finishing: injected color
Material blade: Stainless steel Material bowl: SAN
Material jar: Glass or Plastic Disc storage: Yes
Dishwasher attachments: Yes Cord storage:Yes
Approvals
GS/CE/CB/LVD/EMC/ROHS/LFGB/DGCCRF/REACH/ERP
Parts
A: Body with chopping bowl
B: 1.5 litre Glass Wet Mill attachment
1.5 litre Plastic Wet Mill attachment
C: Dry Mill attachment with filter lid
D: Citrus juicer
E: Centrifugal juicer
F: Metal twin geared whisk
G: 0.5 litre small chopping bowl and blade
H: Plastic chopping blade
Stainless steel chopping blade
I: Spatula
J: Plastic holder with Shred Disc, fine & rough Julienne Disc
Slicer Disc
K. Cubic disc
Meat Mixer,Kitchenaid Grinder,Mixer For Baking,Bread Mixer
Housoen Electric Manufacture Co., Ltd. , https://www.housoenappliances.com