HD66765 Datasheet, PDF (48/71 Pages) Hitachi Semiconductor – 396-channel Segment Driver with Internal RAM for 4096-color Displays

HD66765
Write-data Mask Function
The HD66765 has a bit-wise write-data mask function that controls writing the two-byte data from the
microcomputer to the GRAM. Bits that are 0 in the write-data mask register (WM11–0) cause the
corresponding DB bit to be written to the GRAM. Bits that are 1 prevent writing to the corresponding
GRAM bit to the GRAM; the data in the GRAM is retained. This function can be used when only one-
pixel data is rewritten or the particular display color is selectively rewritten.
DB11
DB0
Data written by
the microcomputer
R03 R02 R01 R00 G03 G02 G01 G00 B03 B02 B01 B00
DB11
DB0
n _{Write-data mask}
111100011100
tio _{GRAM data}
DB11
DB0
* * * * G03 G02 G01 * * * B01 B00
Preliminary ^{Specifica Figure 35 Example of Write-data Mask Function Operation}
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