8.3.1.1 Parallel Interface

The parallel interface complies with standard graphics interface protocol, which includes a vertical sync signal (VSYNC_WE), horizontal sync signal (HSYNC_CS), optional data valid signal (DATAEN_CMD), a 24-bit data bus (PDATA), and a pixel clock (PCLK). The polarity of both syncs and the active edge of the clock are programmable. Figure 5 shows the relationship of these signals. The data valid signal (DATAEN_CMD) is optional in that the DLPC150 provides auto-framing parameters that can be programmed to define the data valid window based on pixel and line counting relative to the horizontal and vertical syncs.

In addition to these standard signals, an optional side-band signal (PDM_CVS_TE) is available, which allows periodic frame updates to be stopped without losing the displayed image. When PDM_CVS_TE is active, it acts as a data mask and does not allow the source image to be propagated to the display. A programmable PDM polarity parameter determines if it is active high or active low. This parameter defaults to make PDM_CVS_TE active high; if this function is not desired, then it should be tied to a logic low on the PCB. PDM_CVS_TE is restricted to change only during vertical blanking.