HD66766R Datasheet, PDF (56/97 Pages) Hitachi Semiconductor – 132 x 176-dot Graphics LCD Controller/Driver for 65K Colors

HD66766R
Rev. 1.0-1 / September 2002
4. Write mode 4: AM = 1, LG2-0 = 110/111
This mode is used when a vertical comparison is performed between the write data and the set value of
the compare resister ( CP15-0 ) to write the data . When the result by the comparison in a byte unit
satisfies the condition, the write data sent from the microcomputer is written to the GRAM. In this
operation, write data mask function ( WM15-0 ) are also enabled. After writing, the address counter
( AC ) automatically increments by 256, and automatically jumps to the upper-right edge ( I/D = 1) or
upper-left edge ( I/D = 0 ) following the I/D bit after it has reached the lower edge of the GRAM.
Operation Examples:
1) I/D = "1", AM = "1" , LG2-0 = "111" ( Unmatched write )
2) WM15-0 = "0000"H
2) CP15-0 = "2860"H
3) AC = "0000"H
WM15
WM0
Write - data mask :
0 0 0 0 0 0 0 00 0 0 00 0 0 0
Compare register :
CP15
CP0
Compare operation
0 0 1 0 1 0 0 00 1 1 0 0 0 0 0
Write data (1) :
Write data (2) :
DB15
( Unmatched )
DB0
1 0 0 1 1 0 0 11 0 0 1 1 1 1 1
( Unmatched )
0 0 1 0 1 0 0 00 1 1 0 0 0 0 0
Conditional replacement
C
R
1 0 0 1 1 0 0 11 0 0 1 1 1 1 1
Compare operation
Conditional replacement
C
R
* * * * ** * * * * * * * * * *
"0000"H
"0001"H
"0000"H
"0100"H
1 0 0 1 1 0 0 1 1 0 0 1 1 1 1 1 ^{Write data (1)}
* * * * * * * * * * * * * * * * ^{Write data (2)}
"AF00"H
GRAM
Notes: 1. The bit area data in the GRAM indicated by (*) is not changed.
2. After writing to address "AF00"H the AC jumps to "0001"H.
Figure 42 Writing Operation of Write Mode 4
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