Epson S1D13705 technical manual Limitations, Default and Alternate Portrait Mode Comparison

Page 42	Epson Research and Development
	Vancouver Design Center

7.5 Limitations

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

Item	Default Portrait Mode	Alternate Portrait Mode
	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
Memory Requirements	320x480x4bpp image would normally	Does not require a virtual image.
	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.
		MCLK, and hence CLK, need to be 2x
		PCLK. For example, if the panel requires a
Clock Requirements	CLK need only be as fast as the	3MHz PCLK, then CLK must be 6MHz.
	required PCLK.	Note that 25MHz is the maximum CLK, so
		PCLK cannot be higher than 12.5MHz in
		this mode.
Power Consumption	Lowest power consumption.	Higher than Default Mode.
Panning	Vertical panning in 2 line increments.	Vertical panning in 1 line increments.
	Nominal performance. Note that	Higher performance than Default Mode.
Performance	performance can be increased by	Note that performance can be increased by
	increasing CLK and setting MCLK =	increasing CLK and setting MCLK = CLK
	CLK (REG[1Bh] bit 2 = 1).	(REG[1Bh] bit 2 = 1).

S1D13705	Programming Notes and Examples
X27A-G-002-03	Issue Date: 02/01/22