
HD61602/HD61603
1252
How to Input HD61603 Data
Input data is composed of 4 bits
×
4. Take care that data transfer is not interrupted, because the first 4-bit
data to the fourth 4-bit data are distinguished from each other by the sequence only.
If data transfer is interrupted, or at power on, the following two methods can be used to reset the count of
the number of data (count of the first 4-bit data to the fourth 4-bit data):
1. Set
&6
and
5(
low.
2. Input 4 or more “1-byte instruction” data (4-bit data) in which bit 3 and 2 are 1 (display data may
change).
The data input method via data input terminals (
&6
,
:(
, D0 to D3) is similar to that of static RAM such
as HM6116. An access of the LSI can be made through the same bus line as ROM and RAM. When
output ports of a microprocessor are used for an access, refer to the timing specifications and Figure 17.
Power on
CS
WE
RE
READY
SYNC
SB
D0–D3
*
6
*
6
*
1
*
4
*
5
*
3
*
2
*
5
*
5
Mode setting data
Mode setting data
Display data
1st 2nd 3rd
4th
1st
2nd 3rd
4th
1st 2nd 3rd
4th
Notes: 1.
2.
3.
4.
5.
6.
7.
READY output is indefinite during 12 clocks after the oscillation start at power on (clock:
OSC2 clock).
High pulse should be applied to SYNC terminal when using two or more chips
synchronously.
In the mode in which READY is always available, READY output is in definite while SYNC
is high.
Reset the 4-bit data counter after power on.
READY output period is within 3.5 clocks in the mode setting operation and bit
manipulation or within 10.5 clocks when the display data (8 bits) is updated.
Connect a pull-up resister if WE or RE may be floating.
It is not always necessary to follow this example.
Figure 17 Example of Data Transfer Sequence