Difference between revisions of "BELK-AN-004: Interfacing BoraEVB/BoraXEVB to TFT LCD display"
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* integrates a pad (denoted as TP1) that is used to connect 5V power supply generated by MOD2 PSU of BoraEVB. This additional power rails is required by display backlight circuitry. | * integrates a pad (denoted as TP1) that is used to connect 5V power supply generated by MOD2 PSU of BoraEVB. This additional power rails is required by display backlight circuitry. | ||
| − | + | The schematics can be downloaded from the following URL: | |
| + | |||
| + | TBD | ||
==Block diagram and Vivado design== | ==Block diagram and Vivado design== | ||
Revision as of 15:14, 1 September 2015
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Contents
History[edit | edit source]
| Version | Date | BELK version | Notes |
|---|---|---|---|
| 1.0.0 | 2.2.0 | First release |
Introduction[edit | edit source]
This application note describes the interfacing of Ampire AM-800480STMQW-TA1 display to BoraEVB. This project is based on BELK 2.2.0.
Physical interfacing[edit | edit source]
To interface the display a small adapter board is needed. It interfaces J22 connector on BoraEVB side and provides a 20-pin connector to directly attach display cable.
The adapter board
- is also equipped with a linear regulator generating 2.5V. This voltage is used as power supply for the VDDIO_BANK13 rail. This voltage is required to implement LVDS differential pairs that drive display.
- integrates a pad (denoted as TP1) that is used to connect 5V power supply generated by MOD2 PSU of BoraEVB. This additional power rails is required by display backlight circuitry.
The schematics can be downloaded from the following URL:
TBD
Block diagram and Vivado design[edit | edit source]
The following picture shows simplified block diagram of the design.
LCD is driven by a controller implemented in PL that fetches pixel data from frame buffer and periodically refreshes physical screen. LCD controller provides configuration registers that are mapped in the following address range: TBD
To implement frame buffer, a portion of main SDRAM is used. This area is allocated at runtime by linux frame buffer driver. Even if LCD is 18 bpp, each pixel is represented by 32-bit word in memory.
At the following URL the Vivado design is available for download: TBD.
Enabling frame buffer driver in linux kernel[edit | edit source]
To enable frame buffer driver TBD
During kernel bootstrap, the following messages are printed out on console, indicating framebuffer driver has been loaded succesfully:
TBD
Once the kernel has completed boot, frame buffer can be accessed from user space applications via /dev/fb0 device file (for more details please refer to https://www.kernel.org/doc/Documentation/fb/framebuffer.txt).
The following image shows Qt 4.??? demo application running on top of it. TBD
