RA8875
Character / Graphic TFT LCD Controller
Version 1.0
5 Pin Definition
5-1 MPU Interface
Pin Name
I/O
Pin Description
Data Bus
These are data bus for data transfer between MPU and RA8875.
When setting register number and register data, DB[7:0] is used.
When writing data to display RAM, DB[15:0] is used according to data
bus mode setting. DB[15:8] will be input and should be pull-low or
pull-high when 8-bits data bus mode is used.
DB[15:0]
IO
Enable/Read Enable
When MPU interface (I/F) is 8080 series, this pin is used as RD# signal
(Data Read) , active low.
When MPU I/F is 6800 series, this pin is used as EN signal (Enable),
active high.
RD#
(EN)
I
Write/Read-Write
When MPU I/F is 8080 series, this pin is used as WR# signal (data write) ,
active low.
When MPU I/F is 6800 series, this pin is used as RW# signal (data
read/write control) . Active high for read and active low for write.
Chip Select Input
Low active chip select pin.
WR#
(RW#)
I
I
CS#
Command / Data Select Input
The pin is used to select command/data cycle. RS = 0, data Read/Write
cycle is selected. RS = 1, status read/command write cycle is selected.
In 8080 interface, usually it connects to “A0” address pin.
RS
0
0
1
1
WR#
Access Cycle
Data Write
Data Read
CMD Write
Status Read
RS
I
0
1
0
1
MPU Interface Select
0: 8080 interface is selected
1: 6800 interface is selected
Parallel /Serial I/F Select Input
0: Parallel 8080/6800 I/F select
1: Serial 3/4-wire SPI or IIC I/F select.
PS input is used to select the active MCU interface, it must be set
correctly before the command /data cycle asserting. We also recommend
that DB[15:0], RD#(EN) , WR#(RW#) ,CS# and RS pin tie to low or high
when using serial I/F.
C86
PS
I
I
Interrupt Signal Output
The interrupt output for MPU to indicate the status of RA8875.
Wait Signal Output
This is a WAIT# output to indicate the RA8875 is in busy state. The
RA8875 can’t access MPU cycle when WAIT# pin is active. It is active low
and could be used for MPU to poll busy status by connecting it to I/O port.
INT#
O
O
WAIT#
4/9
RAiO TECHNOLOGY INC.
www.raio.com.tw
RAIO [ RAIO TECHNOLOGY INC. ]
