HD66773R Datasheet, PDF (74/133 Pages) Renesas Technology Corp – 262,144-color, 132 x 176-dot Graphics Controller Driver for TFT LCD panels

HD66773R
Write-data Mask Function
The HD66773R supports write data mask function, which controls GRAM data write by bit when 16-bit
data from the microcomputer is being written to GRAM. The write data mask function write data in the bits
whose corresponding bits in the write data mask resister (WM15–0) are assigned with “0”. It does not
write data in the bits whose corresponding bits in the write data mask register (WM15–0) are assigned with
“1”, and the corresponding data in GRAM are not overwritten but retained. This function is useful when
only one-pixel data are rewritten or a particular color in the display is selectively changed.
DB17
DB10 DB8
DB1
Data written by the
microcomputer
R04 R03 R02 R01 R00 G05 G04 G03 G02 G01 G00 B04 B03 B02 B01 B00
WM15
Write-data mask 1 1 1 1 1
WM0
0 0 0 0 00 1 1 1 1 0
GRAM data
DB15
**
**
* ^{G05 G04 G03 G02 G01} G00 * * *
DB0
* ^B00
Note) Write data mask function is available with 8/16-bit system interface.
Rev.1.10, Jun.21.2003, page 74 of 133