RA8815
Preliminary Version 2.1
128x33 Character/Graphic LCD Driver
4. Block Diagram
The RA8815 is consist of Display RAM, 256Kbyte Font ROM, Command Registers, LCD Controller, LCD
Driver, Voltage Booster, Voltage Regulator, MPU Interface and Key-Scan circuit.
DB[0:7]
RD(EN)
WR(R/W)
CS
D/C(RS)
C86
BIT4
P/S
MPU
I/F
Block
528bytes
Display RAM + Buffer
256bytes
CGRAM
256Kx8 Font ROM
LCDC Control Block
Register
KST[3..0]
KIN[4..0]
INT
IO[7..0]
EL_CHRG
EL_DCHG
RA, RB
CLK_SEL
EXT_CLK
RST
TEST[2..0]
FG
S[1:0]
Test &
Power
Circuit
RC
Oscillator
Voltage
Booster
GPIO
Key Scan
Control
Block
& INT
Block
Cursor
Control
Scroll
Control
Scan
Control
Driver I/F
Voltage
Regulator
Voltage
Follower
VREG
VREF
128
Segment
Drivers
33
Common
Drivers
C[2:1]P C[2:1]M V0~V4 VLCD
SEG0~SEG127
COM0~COM31
COMS_A[1:0]
COMS_B[1:0]
5. Pin Definition
5-1 MPU Interface
Pin Name
DB[7..0]
DB0: SCK
DB1: SDA/SDO
DB2: RS/SDI
DB3:
CS
DB[7:6]: SMOD
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[4:0] are valid, and DB[7:4] have to
keep floating.
When P/
S
is “0”, then the interface between MPU and RA8815 is Serial
Mode. The pins DB[7:6](SMOD[1:0]) are used to select which serial mode:
I/O
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