HD66712 Datasheet, PDF (43/88 Pages) Hitachi Semiconductor – Dot-Matrix Liquid Crystal Display Controller/Driver

HD66712U
B: The character indicated by the cursor blinks when B is 1. The blinking is displayed as switching
between all blank dots and displayed characters at a speed of 370-ms intervals when f_cp or f_OSC is 270 kHz.
The cursor and blinking can be set to display simultaneously. (The blinking frequency changes according
to f_OSC or the reciprocal of f_cp. For example, when f_cp is 300 kHz, 370 × 270/300 = 333 ms.)
Extended Function Set
When the extended register enable bit (RE) is 1, FW, B/W, and NW bit shown below are accessed.
Once these registers are accessed, the set values are held even if the RE bit is set to zero.
FW: When FW is 1, each displayed character is controlled with a 6-dot width. The user font in CGRAM
is displayed with a 6-bit character width from bits 5 to 0. As for fonts stored in CGROM, no display area
is assigned to the left most bit, and the font is displayed with a 5-bit character width. If the FW bit is
changed, data in DDRAM and CGRAM SEGRAM is destroyed. Therefore, set FW before data is written
to RAM. When font width is set to 6 dots, the frame frequency decreases to 5/6 compared to 5-dot time.
See “Oscillator Circuit” for details.
B/W: When B/W is 1, the character at the cursor position is cyclically displayed with black-white
inversion. At this time, bits C and B in display on/off control register are “Don’t care.” When f_CP or f_OSC is
270 kHz, display is changed by switching every 370 ms.
NW: When NW is 1, 4-line display is performed. At this time, bit N in the function set register is “Don’t
care.”
i) Cursor display example
Alternating
display
ii) Blink display example
Alternating
display
iii) White-black inverting
display example
a) Cursor blink width control
i) 5-dot character width
ii) 6-dot character width
b) Font width control
Figure 16 Example of Display Control
406