How to control the display point of the LCD module (128*64 screen)

How to control the display point of the LCD Module

1. display the ram zone ing

For the LCD module, it is very important to understand the relationship between the Display memory in the driver control IC and the points on the LCD glass. This is the basis for compiling the LCD driver program.

The driver control chip has a total of 65 (8page * 8bit + 1) * 132-bit display Ram zone. The display lattice size is 64*128 points, in fact, the RAM zone used in the LCD module is 64*128 characters. It is divided by byte into 8 pages, each of which is 8 rows, each row is 128 (that is, 128 columns ).

The display mode of the driver control chip shows that the point on the screen corresponding to each byte data in the ram zone is vertically arranged, and the low position is above and down.

If you want to light a certain point on the LCD screen, you actually need to set 1 for a single position in the ram area corresponding to the point. Therefore, you need to determine the row address and column address of the point.

The row address of the MzL02-12864 LCD module is actually the page information, each page should have 8 rows; and the column Address indicates the horizontal coordinates of the point, arranged from left to right on the screen, A byte in page corresponds to a column (eight rows, eight vertices), up to 128 columns.

You can control the display of the LCD display in the program based on this relationship.

The character display method in direct filling mode.

 

Ii. Point function: Read-Modify-write

Read-Modify-Write the idea of the dot matrix LCD module driver in monochrome mode: read a byte data corresponding to the point displayed on the LCD screen from the memory byte where the point to be drawn is located, and then the actual bit location of the byte where the point to be drawn is located, change the BIT data and keep the other bit data of the byte unchanged. Then, write the modified byte data back to read its memory location.

Advantages:

1. Display points at any position without affecting the display of points other than the point;

2. Character Display/graphic display built on the basis of the dot painting function can be displayed at any position;

3. The upper-layer plotting and display control procedures built on the basis of this painting point function are concise and easy to understand.

In the color screen, because a vertex corresponds to one or several bytes of data in the video memory, the painting point operation is much simpler, and the color data displayed in the dot will be directly written to the corresponding byte location.