Epson S1D13705 - Manual (Page 140)

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S1D13705 Programming Notes and Examples
X27A-G-002-03 Issue Date: 02/01/22
Example 8: Pan the above portrait mode image to the right by 4 pixels then scroll it
up by 6 pixels.
To pan by four pixels the start address needs to be advanced.
1. Calculate the number of bytes to change start address by.
Bytes = Pixels x BitsPerPixel / 8 = 4 x 4 / 8 = 2 bytes
2. Increment the start address registers by the just calculated value.
In this case the value write to the start address register will be 81h (7Fh + 2 = 81h)
To scroll by 4 lines we have to change the start address by the offset of four lines of display.
1. Calculate the number of bytes to change start address by.
BytesPerLine = LineByteCount = 128
Bytes = Lines x BytesPerLine = 4 x 128 = 512 = 200h
2. Increment the start address registers by the just calculated value
In this case 281h (81h + 200h) will be written to the Screen 1 Start Address register
set.
Set Screen1 Display Start Word Address LSB (REG[0Ch]) to 81h and Screen1 Dis-
play Start Word Address MSB (REG[0Dh]) to 02h.