lc75712e Sanyo Semiconductor Corporation, lc75712e Datasheet - Page 7

• Manufacturer Part Number: lc75712e
• Description: Dot Matrix Vfd Display Controller/driver
• Manufacturer: Sanyo Semiconductor Corporation

4. CGROM (character generator ROM)
5. CGRAM (character generator RAM)
Reset Function
The LC75710NE series accepts a reset when a low level is applied to the RES pin. On a reset the LC75710NE series
creates a display with all VFD lamps turned off. However, note that the values in DCRAM, ADRAM, and CGRAM, as
well as the values of the duty cycle register (intensity) and the grid register (number of digits) are undefined following a
reset. Therefore, before turning on display with a display on/off control instruction, these values must be initialized. In
particular, the following instructions must be executed when power is first applied.
After executing the above instructions the display must be turned on by executing a “Display on/off control” instruction.
Note that incorrect display may occur if the number of displayed digits and the intensity are not set up in advance. This
can occur in cases where a display on/off control instruction is executed before the grid register load and intensity
adjustment instructions are executed. To prevent this problem, always execute the following three instructions together
as a single set.
CGROM is ROM that is used to generate the 160 different 5 7 dot matrix character patterns. It has a capacity of
160 35 bits. When 8-bit character codes are written to DCRAM, the CGROM character pattern corresponding to
this 8-bit character code is displayed at the VFD display position corresponding to the DCRAM address in AC.
Tables 3 to 5 show the correspondence between the character codes and the character patterns.
CGRAM is RAM to which user programs can write arbitrary data. Up to eight 5 7 dot matrix character patterns can
be stored in the CGRAM. CGRAM has a capacity of 8 35 bits.
To display a character pattern stored in CGRAM, write one of the character codes shown at the left of tables 3 to 5 to
DCRAM. The CGRAM character pattern will be displayed at the VFD position corresponding to the DCRAM
address in AC.
• Display blink
• DCRAM data write
• ADRAM data write (if ADRAM is used)
• CGRAM data write (if CGRAM is used)
• Set AC address
• Grid register load
• Intensity adjustment (dimmer)
• Grid register load
• Intensity adjustment (dimmer)
• Display on/off control
LC75710NE, 75711NE, 75712E
Initial state settings
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