ST7066U
#" Character Generator ROM (CGROM)
The character generator ROM generates 5 x 8 dot or 5 x 11 dot character patterns from 8-bit character codes. It
can generate 240 5 x 8 dot character patterns. User-defined character patterns are also available by
mask-programmed ROM.
#" Character Generator RAM (CGRAM)
In the character generator RAM, the user can rewrite character patterns by program. For 5 x 8 dots, eight
character patterns can be written, and for 5 x 11 dots, four character patterns can be written.
Write into DDRAM the character codes at the addresses shown as the left column of Table 4 to show the
character patterns stored in CGRAM.
See Table 5 for the relationship between CGRAM addresses and data and display patterns. Areas that are not
used for display can be used as general data RAM.
#" Timing Generation Circuit
The timing generation circuit generates timing signals for the operation of internal circuits such as
DDRAM, CGROM and CGRAM. RAM read timing for display and internal operation timing by MPU
access are generated separately to avoid interfering with each other. Therefore, when writing data to
DDRAM, for example, there will be no undesirable interference, such as flickering, in areas other than
the display area.
#" LCD Driver Circuit
LCD Driver circuit has 16 common and 40 segment signals for LCD driving. Data from CGRAM/CGROM is
transferred to 40 bit segment latch serially, and then it is stored to 40 bit shift latch. When each common is
selected by 16 bit common register, segment data also output through segment driver from 40 bit segment latch.
In case of 1-line display mode, COM1 ~ COM8 have 1/8 duty or COM1 ~ COM11 have 1/11duty , and in 2-line
mode, COM1 ~ COM16 have 1/16 duty ratio.
#" Cursor/Blink Control Circuit
It can generate the cursor or blink in the cursor/blink control circuit. The cursor or the blink appears in the digit at
the display data RAM address set in the address counter.
V2.0
2001/03/01
12/42
POWERTIP [ POWERTIP TECHNOLOGY ]
