HD66421 Datasheet, PDF (15/46 Pages) Hitachi Semiconductor – (RAM-Provided 160 Channel 4-Level Grey Scale Driver for Dot Matrix Graphics LCD)

Preliminary
Multi-LSI Operation
Using multiple HD66421s 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.
Rev. 1.1E '99.02.10
HD66421
(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
HD66421s and table 2 lists the differences
between master and slave modes.
Dot-matrix Display
50-channel
row output
VCC
M/S
320 x 100
160-channel
column output
HD66421
(Master)
V1O to
V5O
160-channel
column output
V1O to ^HD66421
V5O
(slave)
50-channel
row output
M/S
OSC OSC1 CO M FLM CL1
M FLM CL1 CO OSC1 OSC
Open
Figure 6 Configuration Using Two HD66421s
Table 2 Comparison between Master and Slave Modes
Item
Pin M/S
OSC
CO
FLM, M, CL1
Registers R0, R2 to R15,R17
R1:BIS1, 0
R1:other
R16
Power supply circuit
Master Mode
Must be set high
Oscillation is active
Output
Output signals
Valid
Valid
Valid
Valid
Valid
Slave Mode
Must be set low
Oscillation is active
High-Z
Input signals
Valid
Invalid
Valid
Invalid
Invalid
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