HD66760 Datasheet, PDF (56/105 Pages) Hitachi Semiconductor – 104 X 80-dot Graphics LCD Controller/Driver for 256 Colors

HD66760
3. Write mode 3: AM = 0, LG2–0 = 110/111
This mode is used when the data is horizontally written by comparing the write data and the set value of
the compare register (CP7–0). When the result of the comparison in a byte unit satisfies the condition, the
write data sent from the microcomputer is written to the GRAM. In this operation, the swap function
(SWP) and write-data mask function (WM15–0) are also enabled. After writing, the address counter (AC)
automatically increments by 1 (I/D = 1) or decrements by 1 (I/D = 0), and automatically jumps to the
counter edge one-raster-row below after it has reached the left or right edge of the GRAM.
Operation Examples:
1) I/D = "1", AM = "0", LG2-0 = "110" (matched write), SWP = "0"
2) CP7–0 = "53H"
3) WM15–0 = "0000"H
4) AC = "000"H
WM15
WM0
Write-data mask: _{0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0}
CP7
CP0
Compare register: _{0 1 0 1 0 0 1 1 Compare operation}
DB15
(Matched) DB0
Write data (1): _{1 0 0 1 1 0 0 1 0 1 0 1 0 0 1 1 C}
Conditional replacement
R
* * * * * * * * 0 10 100 1 1
Write data (2):
Compare
operation
00 00 11 1 100 00 0 000
C
Conditional replacement
Replacement
R
** ** ** ** ** ** ** **
Write data (3):
(Matched)
Compare
operation ^{Conditional replacement}
01 0 10 011 10 0 00 11 0
CR
01 01 00 1 1 * * * * * * * *
Replacement
"0000"H
"0001"H
"0002"H
* * * * * * * * 0 10 10 01 1 * * * * * * * * * * * * * * * * ^{01 010 01 1} * * * * * * * *
Matched
replacement of
write data (1)
GRAM
Matched
replacement of
write data (2)
Figure 36 Writing Operation of Write Mode 3