71M6531D Datasheet, PDF (64/115 Pages) Teridian Semiconductor Corporation – Energy Meter IC

Data Sheet 71M6531D/F-71M6532D/F
FDS 6531/6532 005
3. After periods of operation under battery power, the temperature for the time the meter was not po-
wered can be estimated by averaging the temperatures before and after battery operation. Based on
this, the overall correction for the RTC time can be calculated and applied to the RTC after main
power returns to the meter.
3.5 Connecting LCDs
The 71M6531D/F and 71M6532D/F have an on-chip LCD controller capable of controlling static or multip-
lexed LCDs. Figure 31 shows the basic connection for an LCD.
The following dedicated and multi-use pins can be assigned as LCD segment pins for the 71M6531D/F:
• 12 dedicated LCD segment pins: SEG0 to SEG2, SEG7, SEG8, SEG12 to SEG18.
• 7 dual-function pins: SEG3/PCLK, SEG4/PSDO, SEG5/PCSZ, SEG6/PSDI, E_RXTX/SEG9,
E_TCLK/SEG10, and E_RST/SEG11.
• 14 combined DIO and segment pins: SEG24/DIO4 to SEG35/DIO15, SEG37/DIO17, SEG48/DIO28,
SEG49/DIO29 and SEG63/DIO43 to SEG66/DIO46.
The following dedicated and multi-use pins can be assigned as LCD segments for the 71M6532D/F:
• 15 dedicated LCD segment pins: SEG0 to SEG2, SEG8, SEG12 - SEG18, SEG20 - SEG23.
• 9 dual-function pins: MUX_SYNC/SEG7, E_RXTX/SEG9, E_TCLK/SEG10, E_RST/SEG11,
SEG3/PCLK, SEG4/PSDO, SEG5/PCSZ, SEG6/PSDI.
• 43 combined DIO and segment pins, as described in section 1.5.8.
71M6531D/F or 71M6532D/F
LCD
segments
commons
.
Figure 31: Connecting LCDs
3.6 Connecting I²C EEPROMs
I²C EEPROMs or other I²C compatible devices should be connected to the DIO pins DIO4 and DIO5, as
shown in Figure 32.
Pull-up resistors of roughly 10 kΩ to V3P3D (to ensure operation in BROWNOUT mode) should be used
for both SCL and SDA signals. The DIO_EEX register in I/O RAM must be set to 01 in order to convert
the DIO pins DIO4 and DIO5 to I²C pins SCL and SDA.
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