LAPIS Semiconductor ML610421, User Manual, Page: 339 / 437

ML610Q421/ML610Q422/ML610421 User’s Manual
Chapter 26 LCD Drivers
26 – 1
26. LCD Drivers
26.1 Overview
This LSI includes LCD drivers that display the contents that are set in the display register.
The LCD drivers handle the LCD display functions with four blocks.
1. Display registers
2. Display allocation
3. Display control
4. Drivers
Figure 26-1 Configuration of LCD Display Function
The display registers are used to store the contents to be displayed as bit patterns.
The bit pattern storage method depends on the specification of the LCD panel to be used (display pattern and assignment
of the COM pin and SEG pin) and the setting of the display allocation circuit.
The display allocation block controls mapping of the display register for the LCD common/segment.
Using the display allocation register A and B or not using them is selectable. When using them (Set DASN bit of
DSPMOD1 register to “1”), the segment mapping of the display register can be specified in bit units by programming
according to the contents of display allocation registers A and B. Therefore, the display register array can be changed in
flexible and simplify the software process for display (This function is defined as the programmable display allocation
function in the user’s manual). Also, the data specified to the register A and B can be easily prepared by using Oki
semiconductor LCD allocation Tool. Select type 3 for the display register segment map when using the programmable
allocation function. The programmable display allocation function only generates table data can be used for the type 3.
When not using the display allocation register A and B (Set DASN bit of DSPMOD1 register to “0”), select type 2 or type
3 (type 1 is not available on ML610Q421/ML610Q422/ML610421) for display registers segment map and control the
display with the display register only.
The display control circuit generates LCD drive waveforms according to the characteristics of the LCD. A bias, a bias
voltage multiplying clock, a duty, a frame frequency, and a contrast suitable for the LCD panel can be selected.
Note:
- The programmable display allocation function is available only when 1/1~1/8 duty is selected (when using eight COMs
or less for display), it does not work when 1/9~1/16 duty is selected (when using nine COMs or more for display).
- Select type 3 for the display register segment map (Set DADM1 bit of DSPMOD1 register to “1”) when using the
programmable allocation function. Oki semiconductor LCD Tool only generates table data can be used for the type 3.
- When the programmable display function is not used (DASN = “0”), display allocation register A (0F400H to 0F5FFH)
and display allocation register B (0F600H to 0F7FFH) can be used as 1K-byte data memory(RAM).
Display registers
Bias
Bias multiplying clock
Duty
Contrast
Frame frequency
Display allocation
Display control
COM pins
SEG pins
LCD
Panel
Allocation
Register A, B
Type1
or
Type2
or
Typ3
Segment map
configuration
Drivers
0
1
Type 3
Type1 or 2 or 3
Allocation
RAM
Select by DADM1, DADM0,and DASN bit (DSPMOD1 register)
DSPR62
DSPR63
DSPR00
DSPR01
DSPR02
COM driver
SEG driver