HD66724 Datasheet, PDF (22/117 Pages) Hitachi Semiconductor – (Graphics LCD Controller/Driver with Key Scan Function)

HD66724/HD66725
The character pattern data is sent serially through a 72-bit (96-bit) shift register and latched when all
needed data has arrived. The latched data then enables the segment signal drivers to generate drive
waveform outputs.
The shift direction of 72-bit (96-bit) data can be changed by the SGS bit. The shift direction for the
common driver can also be changed by the CMS bit by selecting an appropriate direction for the device
mounting configuration.
When multiplexing drive is not used, or during the standby or sleep mode, all the above common and
segment signal drivers output the GND level, halting the display.
Booster (DC-DC Converter)
The booster doubles or triples a voltage input to the Vci pin. With this, both the internal logic units and
LCD drivers can be controlled with a single power supply. Boost output level from single to triple boost
can be software-selected. For details, see the Power Supply for Liquid Crystal Display Drive section.
V-Pin Voltage Follower
A voltage follower for each voltage level (V1 to V5) reduces current consumption by the LCD drive power
supply circuit. No external resistors are required because of the internal bleeder-resistor, which generates
different levels of LCD drive voltage. This internal bleeder-resistor can be software-specified from 1/2 bias
to 1/6.5 bias, according to the liquid crystal display drive duty value. The voltage followers can be turned
off while multiplexing drive is not being used. For details, see the Power Supply for Liquid Crystal Display
Drive section.
Contrast Adjuster
The contrast adjuster can be used to adjust LCD contrast in 32 steps by varying the LCD drive voltage by
software. This can be used to select an appropriate LCD brightness or to compensate for temperature.
Table 4 DDRAM Addresses and Display Positions
Dis-
play 1st 2nd 3rd 4th 5th 6th 7th 8th 9th 10th 11th 12th 13th 14th 15th 16th
Line Char. Char. Char. Char. Char. Char. Char. Char. Char. Char. Char. Char. Char. Char. Char. Char.
1st 00 01 02 03 04 05 06 07 08 09 0A 0B 0C 0D 0E 0F
2nd 10 11 12 13 14 15 16 17 18 19 1A 1B 1C 1D 1E 1F
3rd 20 21 22 23 24 25 26 27 28 29 2A 2B 2C 2D 2E 2F
4th 30 31 32 33 34 35 36 37 38 39 3A 3B 3C 3D 3E 3F
5th 40 41 42 43 44 45 46 47 48 49 4A 4B 4C 4D 4E 4F
Note:
When SGS = 0, SEG 1/72 (96) to SEG 6/67 (91) appear at the first character at the extreme left of
the screen.
When SGS = 1, SEG 72 (96)/1 to SEG 67 (91)/6 appear at the first character at the extreme left of
the screen.
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