HD66420 Datasheet, PDF (14/52 Pages) Hitachi Semiconductor – (RAM-Provided 160 Channel 4-Level Grey Scale Driver for Dot Matrix Graphics LCD)

HD66420
Multi-LSI Operation
Using multiple HD66420s provides the means for extending the number of display dots. Note the following
items when using the multi-LSI operation.
(1) The master LSI and the slave LSI must be determined; the M/S pin of the master LSI must be set high
and the M/S pin of the slave LSI must be set low.
(2) The master LSI supplies the FLM, M, CL1 and clock signals to the slave LSI via the corresponding
pins, which synchronizes the slave LSI with the master LSI.
(3) All control bits of slave LSI must be set with the same data with that of the master LSI.
(4) All LSIs must be set to LCD off in order to turn off the display.
(5) The standby function of slave LSI must be started up first, and that of the master LSI must be
terminated first.
(6) The power supply circuit of slave LSI stop working, so V1 to V5 levels are supplied from the master
LSI. If the internal power supply circuit can not drive two LSIs, use an external power supply circuit.
Figure 6 shows the configuration using two HD66420s and table 2 lists the differences between master and
slave modes.
40-channel
row output
Dot-matrix Display
320 x 80
160-channel
column output
160-channel
column output
40-channel
row output
HD66420
(Master)
V1O to
V5O
OSC OSC1 CO M FLM CL1
V1O to
V5O
HD66420
(slave)
M FLM CL1 CO OSC1 OSC
Open
Figure 6 Configuration Using Two HD66420s
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