Texas Instruments AM335 Series Technical Reference Manual

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13.3.6.2 Interrupt Sources
13.3.6.2.1 Overview of Interrupt Sources
The interrupt sources include:
• DMA End of Frame 0
• DMA End of Frame 1
• Palette Loaded
• FIFO Underflow
• AC Bias Count
• Sync Lost
• Recurrent Frame Done
• LIDD or Raster Frame Done
13.3.6.2.1.1 DMA End of Frame 0 and End of Frame 1 Interrupt
The DMA End of Frame 0 and End of Frame 1 interrupts are triggered when the DMA module has
completed transferring the contents of a frame buffer bounded by cfg_fb0_base/cfg_bf0_ceil or
cfg_fb1_base/cfg_fb1_ceil.
13.3.6.2.1.2 Palette Loaded Interrupt
When cfg_palmode is set to Palette-only or Palette+data, the Palette Loaded interrupt is triggered when
the palette portion of the DMA transfer has been stored in the Palette RAM.
13.3.6.2.1.3 FIFO Underflow Interrupt
The FIFO Underflow interrupt is triggered when the real-time output needs to send a value for pixel data
but one cannot be found in the FIFO.
13.3.6.2.1.4 AC Bias Count Interrupt
For Passive Matrix displays, a count can be kept of the number of times the AC Bias line toggles. Once
the specified number of transitions has been seen, the AC Bias Count interrupt is triggered. The module
will not post any further interrupts or keep counting AC Bias transitions until the interrupt has been
cleared.
13.3.6.2.1.5 Sync Lost Interrupt
When the DMA module reads a frame buffer and stores it in the FIFO, it sets a start frame and an end
frame indicator embedded with the data. On retrieving the data from the FIFO in the lcd_clk domain, the
Sync Lost interrupt is triggered if the start indicator is not found at the first pixel of a new frame.
13.3.6.2.1.6 Recurrent Frame Done Interrupt
In raster mode, the Recurrent Frame Done interrupt is triggered each time a complete frame has been
sent to the interface pins.
13.3.6.2.1.7 LIDD or Raster Frame Done Interrupt
In LIDD DMA mode, a frame buffer of data is sent. When the frame buffer has completed, the LIDD Frame
Done interrupt is triggered. In order to do another LIDD DMA, the DMA engine must be disabled and then
re-enabled.
In Raster mode, the interrupt is triggered after cfg_lcden is set to ‘0’ and after the last frame is sent to the
pins. After the Raster mode DMA is running, the interrupt occurs only once after the module is disabled.
1120
LCD Controller SPRUH73H–October 2011–Revised April 2013
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Texas Instruments AM335 Series Specifications

General

Brand	Texas Instruments
Model	AM335 Series
Category	Computer Hardware
Language	English