71M6541D Datasheet, PDF (66/166 Pages) Maxim Integrated Products – 0.1% Accuracy Over 2000:1 Current Range Energy Meter ICs

71M6541D/F/G and 71M6542F/G Data Sheet
The LCD system has the ability to drive up to six segments per SEG driver. If the display is configured with
six back planes, the 6-way multiplexing compresses the number of SEG pins required to drive a display and
therefore enhance the number of DIO pins available to the application. Refer to the LCD_MODE[2:0] field
(I/O RAM 0x2400[6:4]) settings (Table 57) for the different LCD multiplexing choices. If 5-state
multiplexing is selected, SEGDIO27 is converted to COM4. If 6-state multiplexing is selected, SEGDIO26
is converted to COM5. These conversions override the SEG/DIO mapping of SEGDIO26 and SEGDIO27.
Additionally, independent of LCD_MODE[2:0], if LCD_ALLCOM = 1, then SEGDIO26 and SEGDIO27
become COM4 and COM5 if their LCD_MAP[ ] bits are set.
The LCD_ON (I/O RAM 0x240C[0]) and LCD_BLANK (I/O RAM 0x240C[1]) bits are an easy way to either
blank the LCD display or turn it fully on. Neither bit affects the contents of the LCD data stored in the
LCDSEG_DIO[ ] registers. In comparison, LCD_RST (I/O RAM 0x240C[2]) clears all LCD data to zero.
LCD_RST affects only pins that are configured as LCD.
A small amount of power can be saved by programming the LCD frequency to the lowest value
that provides satisfactory LCD visibility over the required temperature range.