DLPU115 January 2022 DLPC3421
Commands that take a long time to process, require a lot a data to be loaded from flash, or change the frame timing of the system may create on-screen artifacts. The Write Image Freeze command can try and minimize, if not eliminate, these artifacts. The process is:
Because commands to the controller process serially, no special timing or delay is required between these commands. The number of commands placed between the freeze and unfreeze must be small, as it is not desirable for the image to be frozen for a long period of time. A list of commands that may produce image artifacts is listed in Table 3-18, which is not an all-inclusive list. The user is responsible for determining the correct use of the image freeze command.
Command | Command OpCode | Notes |
---|---|---|
Write Input Source Select | 05h | |
Write External Video Source Format Select | 07h | If changed while this source is the active source, embedded software disables image freeze after this command is executed |
Write Test Pattern Select | 0Bh | If changed while this source is the active source |
Write Splash Screen Select | 0Dh | If changed while this source is the active source, embedded software disables image freeze after this command is executed |
Write Look Select | 22h |
Table 3-19 and Table 3-20 show a few examples of how to use the image freeze command.
Command | Notes |
---|---|
Write Display Image Curtain = enable | May want to apply curtain if already displaying an unwanted image (such as a broken source) |
Write Image Freeze = freeze | |
Write Image Crop, Write Display Size, Write Display Image Orientation | Potential data processing commands that may be required for proper display of splash image. These must be set prior to write splash screen execute command to affect the splash screen image. |
Write Splash Screen Select Write Input Source Select = splash | These must be set prior to write splash screen execute |
Write Splash Screen Execute | Retrieves the desired splash screen image for display |
The new splash image displays when the Write Splash Screen Execute command executes, regardless of the state of the Write Image Freeze command (due to the one time nature of the splash image). Embedded software disables image freeze after this command is executed.
Command | Notes |
---|---|
Write Image Freeze = freeze | |
Write Image Crop, Write Display Size, Write Display Image Orientation, Write Test Pattern Select | Potential data processing commands that may be required for proper display of test pattern image. These must be set before the Write Input Source Select command. |
Write Input Source Select = test pattern generator | |
Write Image Freeze = unfreeze |