CHAPTER 3: PERIPHERAL CIRCUITS (LCD Driver)
II-29
The E0C6001 contains 128 bits of display memory in ad-
dresses 090H to 0AFH of the data memory. Each display
memory can be assigned to any 80 bits of the 128 bits for
the LCD driver (20 SEG
×
4 COM), 60 bits of the 128 bits (20
SEG
×
3 COM) or 40 bits of the 128 bits (20 SEG
×
2 COM)
by using a mask option. The remaining 48 bits, 68 bits or 88
bits of display memory are not connected to the LCD driver,
and are not output even when data is written. An LCD
segment is on with "1" set in the display memory, and off
with "0" set in the display memory. Note that the display
memory is a write-only.
• LCD drive control register (CSDC)
The LCD drive control register (CSDC: address 0FBH, D3)
can set the 1/1 duty drive. Set "0" in CSDC for 1/4 duty, 1/3
duty or 1/1 duty drive. Set "1" in CSDC and the same value
in the registers corresponding to COMs 0 through 3 for 1/1
duty drive.
Figure 3.5.2 shows the 1/1 duty drive waveform (1/3 bias)
and Figure 3.5.3 shows an example of the 7-segment LCD
assignment.
See page I-41 for the 1/1 duty drive waveform (1/2 bias).
Control of the LCD
driver