71M6541F Maxim, 71M6541F Datasheet - Page 66

• Manufacturer Part Number: 71M6541F
• Description: The 71M6541D/71M6541F/71M6541G/71M6542F/71M6542G are Teridian™ 4th-generation single-phase metering SoCs with a 5MHz 8051-compatible MPU core, low-power RTC with digital temperature compensation, flash memory, and LCD driver
• Manufacturer: Maxim

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
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.
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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.
(Table
57) for the different LCD multiplexing choices. If 5-state
Rev 2