SED1374 Datasheet, PDF (132/420 Pages) Epson Company – SED1374 Embedded Memory Color LCD Controller

Page 36
7 SwivelView™
Epson Research and Development
Vancouver Design Center
7.1 Introduction To SwivelView
Many of todays applications use the LCD panel in a portrait orientation. In this case it
becomes necessary to “rotate” the displayed image. This rotation can be done by software
at the expense of performance or, as with the SED1374, it can be done by hardware with
no performance penalty.
There are two hardware rotated modes: Default SwivelView Mode and Alternate
SwivelView Mode.
7.2 Default SwivelView Mode
Default SwivelView Mode requires the portrait image width be a power of two, e.g. a 240-
line panel requires a minimum virtual image width of 256. This mode should be used
whenever the required virtual image can be contained within the integrated display buffer
(i.e. virtual image size ≤ 40k bytes), as it consumes less power than the Alternate
SwivelView mode.
For example, the panel size is 320x240 and the display mode is 4 bit-per-pixel. The virtual
image size is 320x256 which can be contained within the 40k Byte display buffer.
Default SwivelView Mode also requires memory clock (MCLK) ≥ pixel clock (PCLK).
SED1374
X26A-G-002-02
Programming Notes and Examples
Issue Date: 99/04/27