ra8825 RAIO Technology Inc., ra8825 Datasheet - Page 4

• Manufacturer Part Number: ra8825
• Description: 128x33 Dot Matrix Lcd Driver
• Manufacturer: RAIO Technology Inc.

Preliminary Version 1.1
5-1 MPU Interface
RAiO TECHNOLOGY INC.
DB0: SCK
DB1: SDA/SDO
DB2: RS/SDI
DB3: CS
DB[7:6]: SMOD
Pin Name
DB[7..0]
R/
D/
EN
RS
CS
I/O
I/O
O
I
I
I
I
Data Bus
When the MPU use parallel mode and 8-bit then all of the DB[7:0] are
valid. When use 4-bit then only DB[4:0] are valid, and DB[7:4] have to
keep floating.
When P/ S is “0”, then the interface between MPU and RA8825 is Serial
Mode. The pins DB[7:6](SMOD[1:0]) are used to select which serial mode:
SMOD :
-----------------------------------------------------------------
In serial mode, all of the related signals are defined by DB[3:0]:
SCK(DB0) : Serial Clock.
SDA(DB1) : Bi-direction Mode Serial Data.
SDO(DB1) : Data Out.
RS(DB2)
SDI(DB2) : Serial Data In.
The unused pin must keep NC for serial mode.
Read Control or Enable
When use 8080 series interface,
When use 6800 series interface, EN is the Enable signal and active high.
Connect this pin to VDD for serial mode.
Write Control or Read-Write Control
When use 8080 series interface,
When use 6800 series interface, this pin is R/
cycle and active low for write cycle.
Connect this pin to VDD for serial mode.
Data/Command Select or Register Select)
When use 8080 series interface, this is Data or Command signal. When
D/ C is “0”, means Register Cycle(or Command Cycle). When D/ C is
“1”, means Data Access Cycle(Data Cycle).
When use 6800 series interface, this is the RS signal. When RS is “0”,
means Register Cycle and “1” means Data Access Cycle.
Connect this pin to VDD for serial mode.
Chip Select
This is a chip enable for RA8825.
Connect this pin to VDD for serial mode.
Interrupt Signal
This is an interrupt output for MPU. Active low。
CS (DB3) : Chip Select, active low.
0 X : 3-Wire, SCK, SDA,
1 0 : 4-Wire, SCK, SDA, RS,
1 1 : 4-Wire, SCK, SDO, SDI, CS are used.
6. Pin Definition
: Memory/Register Cycle Select.
Serial Mode
4/6
Description
are used.
is the read signal and active low.
are used.
is the write signal and active low.
128x33 Graphic LCD Driver
, active high for read
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RA8825