Microchip Graphics Suite (MGS) Display Timing Guide
Introduction
Depending on the device, Microchip Graphics Suite (MGS) Harmony provides device-specific drivers that can be used to configure the Red, Green and Blue (RGB) interface and timing to an RGB display.
On most graphics-enabled MCUs or MPUs, a dedicated driver is provided for the specific peripheral that's used to drive the display. Examples are LCD Controller (LCDC) or Graphics LCD (GLCD) display drivers.
Setting the Pixel Clock
The pixel clock configuration is device and peripheral-dependent.
For more detailed information about the display drivers, refer to the device-specific guide on the "Microchip Graphics Suite (MGS) Development Kits" page.
Integrated Display Controllers
For devices with integrated display controllers, a clock source is provided to the display controller peripheral. The frequency of this clock source is configured using the Clock Configurator in MPLAB® Code Configurator (MCC) Harmony.
If a clock divider is available in the display controller peripheral, the MCC display driver component will provide a setting for the divider to configure the pixel clock frequency.
Here's an example of the clock source and clock divider setting for the MCC display driver for the LCDC peripheral.
Low Cost Controller-less (LCC)
LCC-based drivers provide very limited control for changing the pixel clock. Since LCC uses a Direct Memory Access (DMA) and an 8- or 16-bit parallel port peripheral (e.g., External Bus Interface (EBI)), it may be possible to change the write frequency to change the effective pixel clock. This may include using a timer as the DMA trigger source and changing the timer frequency or changing the parallel port peripheral timing.
Setting the Display Timing
To configure the display driver for third-party displays, it is necessary to change the display control timing to match the display specifications.
The GFX Core LE component in MCC Harmony provides the configuration options for the display timing used in the generated drivers, whether for integrated controllers or LCC. Set these to match the timing requirements of the target display.
