HD66765 Datasheet, PDF (53/71 Pages) Hitachi Semiconductor – 396-channel Segment Driver with Internal RAM for 4096-color Displays

HD66765
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 register (CP11–0) 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, the write-data mask function (WM11–0) 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)
n _{2) CP11—0 = "530"H}
tio ^{3) WM11—0 = "000"H}
4) AC = "0000"H
a ^DB11
DB0
ific ^{Write-data mask: 0 0 0 0 0 0 0 0 0 0 0 0}
DB11
DB0
c ^{Compare register:}
e _{Write data (1):}
Sp _{Write data (2):}
010100110000
(Unmatched)
Compare
operaton
100110011001
C
(Matched)
010100110000
Compare
operaton
C
Conditional
replacement
R
Conditional
replacement
R
100110011001
************
ary _{"0000"H 1 0 0 1 1 0 0 1 1 0 0 1 Write data (1)}
in _{"0001"H * * * * * * * * * * * *}
Prelim ^"AF00"H
GRAM
Figure 39 Writing Operation of Write Mode 4
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