Epson S1D13705 - page 135

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Vancouver Design Center
Programming Notes and Examples S1D13705
Issue Date: 02/01/22 X27A-G-002-03
The portrait mode select bit selects between the “Default Mode ” and the “ Alternate Mode ”.
Setting this bit to “0” selects the default portrait mode while setting this bit to “1” enab les
the alternate portrait mode.
Portrait Mode Memory Clock Select is another power saving measure which can be enabled
if the final MCLK value is less than or equal to 25 MHz. Memory Clock Select results in
the S1D13705 temporarily increasing the memory clock circuitry on CPU access and
resuming the slower speed when the access is complete. This re sult s in bette r per formanc e
while using the least power.
In portrait display mode the CLKI (input clock) is routed to the portrait section of the
S1D13705 as CLK. From the CLK signal the MCLK value can be determined from table
8-8 of the Hardware Functional Specification, document number X27A-A-001-xx. If
MCLK is determined to be less than or equal to 25 MHz then Portrait Mode Memory Cl ock
Select may be enabled.