S1D13705 Epson Electronics America, Inc., S1D13705 Datasheet - Page 134

• Manufacturer Part Number: S1D13705
• Description: S1d13705 Embedded Memory Lcd Controller
• Manufacturer: Epson Electronics America, Inc.

Page 42
7.5 Limitations
S1D13705
X27A-G-002-02
Memory Requirements
Clock Requirements
Power Consumption
Panning
Performance
Item
The only limitation to using portrait mode on the S1D13705 is that split screen operation is
not supported.
A comparison of the two portrait modes is as follows:
Table 7-1: Default and Alternate Portrait Mode Comparison
The width of the rotated image must be
a power of 2. In most cases, a virtual
image is required where the right-hand
side of the virtual image is unused and
memory is wasted. For example, a
320x480x4bpp image would normally
require only 76,800 bytes - possible
within the 80K byte address space, but
the virtual image is 512x480x4bpp
which needs 122,880 bytes - not
possible.
CLK need only be as fast as the
required PCLK.
Lowest power consumption.
Vertical panning in 2 line increments.
Nominal performance. Note that
performance can be increased by
increasing CLK and setting MCLK =
CLK (REG[1Bh] bit 2 = 1).
Default Portrait Mode
Does not require a virtual image.
MCLK, and hence CLK, need to be 2x
PCLK. For example, if the panel requires a
3MHz PCLK, then CLK must be 6MHz.
Note that 25MHz is the maximum CLK, so
PCLK cannot be higher than 12.5MHz in
this mode.
Higher than Default Mode.
Vertical panning in 1 line increments.
Higher performance than Default Mode.
Note that performance can be increased by
increasing CLK and setting MCLK = CLK
(REG[1Bh] bit 2 = 1).
Alternate Portrait Mode
Epson Research and Development
Programming Notes and Examples
Vancouver Design Center
Issue Date: 01/02/13