EM65568 Datasheet, PDF (24/112 Pages) ELAN Microelectronics Corp – 130 COM/ 128 SEG 4096 Color STN LCD Driver

EM65568
130 COM/ 128 SEG 4096 Color STN LCD Driver
Read display RAM operation
WRB
D0~D7
(D0~D15)
RDB
n
Address set (AX,AY)
Address = n
***
Dummy
Read
RS
n
Data Read
Address=n
n+1
Data Read
Address=n+1
n+2
Data Read
Address=n+2
Figure 7. Read display RAM operation
The EM65568 can be read the control registers, in case of control register read operation, data bus upper nibble (D7-D4) use
for register address (0 to FH). In maximum, 16 registers can access directly. But number of register is more than 16 registers.
Therefore, EM65568 has register bank control. The RE register is set bank number to access. And the RE address is 0FH, in
any bank can access RE register. It is need 4-steps to read the specific register in maximum case.
(1) Write 04H to RE register for access to RA register.
(2) Writes specific register address to RA register.
(3) Write specific register bank to RE register.
(4) Read specific register contents.
Register read operation
WRB
D0~D7
RDB
RS
04H
addr
Bank number write Address write
to RE for RA
to RA
bank
Bank number
write to RE
data
read specific
register
Figure 8. Register read operation
7.4 16-bit Data Access to Display RAM
The EM65568 correspond to 8-bits and 16-bits bus size access.
The data bus size can select by WLS register.
WLS = “0”: 8-bits bus size
WLS = “1”: 16-bits bus size
In the 16-bits access mode, access for control register use low-byte data bus (D7~D0). Then high byte data bus (D15~D8) are
not used in internal circuit. When read control register using 16-bits bus. Register values output to D3-D0 and D15-D4 output
“H”.
* This specification is subject to be changed without notice. 24
2005/3/8 (V1.2)