em65567 ELAN Microelectronics Corp, em65567 Datasheet - Page 21

• Manufacturer Part Number: em65567
• Description: Com/ Color Driver
• Manufacturer: ELAN Microelectronics Corp

The EM65567 can be read the control registers, in case of control register read operation, data bus upper nibble (D3-D0) use
for register address (0 to FH). In maximum, 16 registers can access directly. But number of register is more than 16 registers.
Therefore, EM65567 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.
Register read operation
7.4 16-bit Data Access to Display RAM
The EM65567 correspond to 8-bits and 16-bits bus size access.
The data bus size can select by WLS register.
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”. 16-bit access is only effective for access to the display RAM.
7.5 Display Start Address Register
This register determines the Y-address of the display RAM corresponding to the display start line. The display RAM data that
addressed Display Start Address register output to common driver start line. The actual common start line of LCD panel
depend on Display Start Common register and SHIFT bit of Display Control register. The register are preset every timing of
FLM signal variation in the display line counter. The line counter counts up being synchronized with LP input and generates
line addresses which read out sequentially 288 bits data from display RAM to LCD drive circuit.
7.6 Addressing of Display RAM
The EM65567 has built-in bit mapped display RAM. The display RAM consists of 768 bits (8 bits*96) in the X-direction and
66 bits in the Y-direction. In the gradation display mode, the EM65567 provides segment driver output for 8-gradation
display using 3 bits and that for 4-gradation display using 2 bits. The three outputs of the segment driver can be used for one
pixel of RGB. When connected to an STN color LCD panel, the EM65567 can display 96*66 pixels with 256 colors (8
* This specification is subject to be changed without notice.
(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.
WLS = “0”: 8-bits bus size
WLS = “1”: 16-bits bus size
D 0~D 7
W R B
R D B
R S
Bank number write
to RE for RA
Figure 8. Register read operation
04H
Address write
addr
to RA
21
66 COM/ 96 SEG 256 Color STN LCD Driver
Bank number
write to RE
bank
read specific
register
data
2003/1/9 (V0.1)
EM65567