Liquid Crystal Display Controller (LCDC)
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20.2.1.1
Data Path
There are two data paths, which are shown in Fig 20-4.
Data path 1: DMA mode
The path is Memory -> AXI Master -> LCDC -> LCD. This path is used for RGB I/F and MCU I/F DMA mode.
Data path 2: MCU I/O mode
The path is CPU -> APB Slave -> LCDC -> LCD. This path is used for MCU I/F I/O mode, such as read/write point from LCD internal GRAM or send
command to LCD.
I/F
Control
(RGB/MCU)
AXI
Master
Config register
AXI
Slave
LCD
DMA Module
RGB565
RGB565
Image DMA FIFO
Path 1
Path 2
Fig 20-4 Two data paths
20.2.1.2
MCU I/O Mode
MCU I/O mode is just used for MCU I/F. The application scenario is shown in Fig 20-5.
Frame Buffer
Ameba-D
LCM
Display Glass
Display Control
LCDC
I8080 Control & DATA
Fig 20-5 MCU I/O mode application scenario
When you use LCM (Liquid Crystal Module) with internal GRAM, you can use MCU I/F to control the image display and send image to LCD
GRAM one pixel by one pixel.
If you only want to update partial image, write/read only one pixel to/from LCM. This is useful under menu development.
In this mode, you don’t need to allocate a frame buffer in Ameba-D.
20.2.1.2.1
I/O Tx Mode
Every time software writes data register, the data is stored in I/O Tx FIFO temporally. and sent through hardware when MCU interface is idle.
When I/O Tx FIFO is full, I/O write action halts. When Tx FIFO isn`t full, write ready signal is given by hardware and then software can write
another pixel data.
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2019-05-15 10:08:03