HD66420 Datasheet, PDF (18/52 Pages) Hitachi Semiconductor – (RAM-Provided 160 Channel 4-Level Grey Scale Driver for Dot Matrix Graphics LCD)

HD66420
Word Length
The HD66420 can handle either 8- or 6-bits as a word. In the display memory, one X address is assigned to
each word of 8- or 6-bits long in X direction.
When the 6-bits mode is selected, only data on DB5 to DB0 are used and data on DB7 and DB6 are
discarded. This word length is only applied to data to internal RAM. The word length of internal register is
always 8-bits
SEG1
H’00
H’01
8 bits
LCD drive signal output
SEG160 SEG1
H’00
H’01
6 bits
LCD drive signal output
SEG160
H’4E
H’4F
H’0
MSB
H’1
X addresses
H’4E
H’4F
H’27
H’0 H’1
MSB
H’34 H’35
X addresses
(a) Address assignment when one
word is 8 bits long
(b) Address assignment when one
word is 6 bits long
Figure 9 Display RAM Addresses
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