RA8816
Preliminary Version 1.6
144x65 Character/Graphic LCD Driver
4. Pin Definition
4-1 MPU Interface
Table 4-1
Pin Name
I/O
Description
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[3..0] are valid, and DB[7..4] have to
keep floating.
When P/
S
is “0”, then the interface between MPU and RA8816 is Serial
Mode. The pins DB[7..6](SMOD[1..0]) are used to select which serial
mode:
SMOD :
Serial Mode
-----------------------------------------------------------------
0 0 : IIC interface,
SCK,
SDA are used
0 1 : 3-Wire,
SCK,
SDA,
CS
are used.
I/O
1 0 : 4-Wire,
SCK,
SDA, RS,
CS
are used.
1 1 : 4-Wire,
SCK,
SDO, SDI,
CS are used.
DB[7..0]
DB0: SCK
DB1: SDA/SDO
DB2: RS/SDI
DB3:
CS
DB[7..6]: 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) : Memory/Register Cycle Select.
SDI(DB2) : Serial Data In.
CS (DB3) : Chip Select, active low.
In the IIC mode,
WR
,
RD
and DB[5..2] are used as the IIC device
address - IICA[5..0] to avoid conflict with other IIC devices.
The unused pin must keep NC for serial mode.
Read Control or Enable
RD
EN
I
When use 8080 series interface,
RD
is the read signal and active low.
When use 6800 series interface, EN is the Enable signal and active high.
In the IIC mode,
RD
is used as IIC device address - IICA[4].
This pin must keep NC for 3 or 4-wires serial mode.
Write Control or Read-Write Control
When use 8080 series interface,
WR
is the write signal and active low.
WR
R/
W
I
When use 6800 series interface, this pin is R/
W
, active high for read
cycle and active low for write cycle.
In the IIC mode,
WR
is used as IIC device address - IICA[5].
This pin must keep NC for 3 or 4-wires serial mode.
Data/Command Select or Register Select)
When use 8080 series interface, this is Data or Command signal. When
D/
C
RS
I
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”,
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