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S-MOS Systems, Inc. 2460 North First Street San Jose, CA 95131 Tel: (408) 922-0200 Fax: (408) 922-0238
22
268-0.4
2.0 Pin Description
2.4.3
Pin Name
Function
A0, in conjunction with the RD and WR or R/W and E signals, controls the type of access to
the SED1336F, as shown below.
8080 family interface
A0
0
1
0
1
RD
0
0
1
1
WR
1
1
0
0
Function
Status flag read
Display data and cursor address read
Display data and parameter write
Command write
6800 family interface
A0
0
1
0
1
R/W
1
1
0
0
E
1
1
1
1
Function
Status flag read
Display data and cursor address read
Display data and parameter write
Command write
When the 8080 family interface is selected, this signal acts as the active-LOW read strobe. The
SED1330F/1335F/1336F’s output buffers are enabled when this signal is active.
When the 6800 family interface is selected, this signal acts as the active-HIGH enable clock.
Data is read from or written to the SED1330F/1335F/1336F when this clock goes HIGH.
When the 8080 family interface is selected, this signal acts as the active-LOW write strobe. The
bus data is latched on the rising edge of this signal.
When the 6800 family interface is selected, this signal acts as the read/write control signal. Data
is read from the SED1330F/1335F/1336F if this signal is HIGH, and written to the SED1330F/
1335F/1336F if it is LOW.
Chip select. This active-LOW input enables the SED1330F/1335F/1336F. It is usually
connected to the output of an address decoder device that maps the SED1330F/1335F/1336F
into the memory space of the controlling microprocessor.
This active-LOW input performs a hardware reset on the SED1330F/1335F/1336F. It is a
Schmitt-trigger input for enhanced noise immunity; however, care should be taken to ensure
that it is not triggered if the supply voltage is lowered.
WR or R/W
CS
RES
RD or E
A0