ra8835 Topway Display, ra8835 Datasheet - Page 8

• Manufacturer Part Number: ra8835
• Description: Dot Matrix Lcd Controller
• Manufacturer: Topway Display

RAiO TECHNOLOGY INC.
Version 1.7
5-1-2 Display Memory Control
The RA8835 series can directly access static RAM and PROM. The designer may use a mixture of
these two types of memory to achieve an optimum trade-off between
consumption.
VA0 to
VD0 to
Name
VA15
VWR
R/ W
RES
VRD
VCE
VD7
WR
Pin
CS
A0
or
Write Control or Read/Write Control.
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 RA8835 series if this signal is HIGH, and written to the
RA8835 series if it is LOW.
Chip Select.
This active-LOW input enables the RA8835 series. It is usually connected to the
output of an address decoder device that maps the RA8835 series into the memory
space of the controlling microprocessor.
Command/Data Select.
8080 Family Interface:
6800 Family Interface:
Hardware Reset.
This active-LOW input performs a hardware reset on the RA8835 series. It is an
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.
16-bit Display Memory Address.
When accessing character generator RAM or ROM, VA0 to VA3, reflect the lower 4
bits of the RA8835 series’ row counter.
Display Memory Data Bus.
8-bit tristate display memory data bus. These pins are enabled when VR/ W is LOW.
Display Memory Write Control.
Active-LOW display memory write control output.
Display Memory Read Control.
Active-LOW display memory read control output.
Display Memory Chip Select.
Active-LOW static memory standby control signal. VCE can be used with CS .
A0
A0
0
1
0
1
0
1
0
1
R/ W
RD
0
0
1
1
1
1
0
0
8/86
WR
E
1
1
0
0
1
1
1
1
Function
Display data and cursor address read
Display data and cursor address read
Display data and parameter write
Display data and parameter write
Status flag read
Command write
Status flag read
Command write
Function
Function
Dot Matrix LCD Controller
low cost and low power
www.raio.com.tw
RA8835