Epson S1D13705 technical manual Epson Research and Development

Epson Research and Development	Page 41
Vancouver Design Center

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” enables 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 results in better performance 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 Clock Select may be enabled.

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