HD66789 Datasheet, PDF (110/156 Pages) Renesas Technology Corp – 528-channel, One-chip Driver for Amorphous TFT Panels with 262,144-color display RAM, Power Supply Circuit, and Gate Circuit

HD66789
Preliminary
4. Write mode 4: AM = 1, LG2–0 = 110/111
This mode is used when data are horizontally written with comparing the write data and the value set in the
compare register (CP17–0) by R, G, B pixel. When the result of the comparison satisfies a condition, the
write data sent from the microcomputer are written to GRAM. The write-data mask function (WM17–0) is
also available with this mode. After writing, the address counter (AC) automatically increments by 256,
and automatically jumps to the counter either at the top of the next right row (ID = 1) or at the top of the
next left row (I/D = 0) according to the setting in the I/D bit, when the address reaches the bottom of
GRAM.
Operation example
1) I/D = "1", AM = "1", LG2-0 = "111" (unmatched writing)
2)CP17-0 = "0A0C0"H
3)WM17-0 = "00000"H
4) AC = "0000"H
WM17
WM0
Write-data mask: _{0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0}
CP17
CP0
Compare register: _{0 0 1 0 1 0 0 0 0 0 1 1 0 0 0 0 0 0} ^{Compare operation}
DB17
(Unmatched)
DB0
Write-data (1): _{1 0 0 1 1 1 0 0 1 1 0 0 1 1 1 1 1 1} C
Conditional replacement
R 100111001100111111
Write-data (2):
(Matched)
Compare
operation
Replacement
Conditional replacement
001010000011000000 C R * * * * * * * * * * * * * * * * * *
Data are expanded into 18 bits in 8/16-bit system
interface, and 16-bit RGB interface modes.
"0000"H
"0100"H
"0000"H ^{0 0 1 0 0 1 1 0 0 1 1 0 0 1 1 1 1 1 Write-data (1)}
"0100"H * * * * * * * * * * * * * * * * * * ^{Write-data (2)}
"EF00"H
GRAM
Note 1) The bits in the GRAM with “*”are not overwritten.
Note 2) After writing data to the address "EF00"H, the address counter jumps to
"0001"H.
Write Mode 4
Rev.0.12, May 09 2003, page 110 of 156