HD66731A01TB0L datasheet(21/131 Pages) HITACHI

21 / 131 page

HD66730/HD66731

Timing Generator

The timing generator generates timing signals for the operation of internal circuits such as DDRAM,

FCGROM, HCGROM, CGRAM, and SEGRAM. RAM read timing for display and internal operation

timing for MPU access are generated separately to avoid interference. This prevents undesirable

interferences, such as flickering, in areas other than the display area when writing data to DDRAM, for

example.

The timing generator of HD66730 generates interface control signals CL1, CL2, M, and COMD-output of

extension drivers for a extension configuration.

Display Attribute Controller

The display attribute controller displays white/black inverse, blinking, and white/black inverse blinking for

a full size font in FCGROM according to the attribute code set in the DDRAM. Refer to Display Attribute

Designation for details.

Fonts in CGRAM and bit patterns in SEGRAM control display attributes using the upper two bits (bits 7

and 6) in each display-pattern data.

Cursor Control Circuit

The cursor control circuit is used to produce a cursor on a displayed character corresponding to the

DDRAM address set in the RAM address counter (RAR). Cursors can be chosen from three types: 12th

raster-row cursor that is displayed only on the 12th raster-row of each font; blink cursor that periodically

displays the whole font in black and white and black inverted cursor that periodically displays the font in

white and black (see Figure 9). Note that when the RAM address counter (RAR) is selecting CGRAM or

SEGRAM, a cursor would be generated at that address, however, it does not have any meaning.

Note:

One display line consists of 13 raster-rows.

Smooth Scroll Control Circuit

The smooth scroll control circuit is used to perform a smooth-scroll in units of dots.

When the number of characters to be displayed is greater than that possible at one time in the liquid crystal

module, this horizontal smooth scroll can be used to display characters in an easy-to-read manner for each

line. Refer to Horizontal Smooth Scroll for details for each line.

HD66731A01TB0L Datasheet(PDF) 21 Page - Hitachi Semiconductor