71M6533 Datasheet, PDF (73/132 Pages) Teridian Semiconductor Corporation – Energy Meter IC

FDS_6533_6534_004
71M6533/71M6534
71M6533/G/H and 71M6534/H Data Sheet
LCD
segments
commons
Figure 36: Connecting LCDs
4.3 Connecting I²C EEPROMs
I²C EEPROMs or other I²C compatible devices should be connected to the DIO pins DIO4 and DIO5, as
shown in Figure 37.
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[1:0] register in I/O RAM must be set to 1 in order to convert
the DIO pins DIO4 and DIO5 to I²C pins SCL and SDA.
10 kΩ
DIO4
DIO5
V3P3D
10 kΩ
EEPROM
SCL
SDA
71M6533/71M6534
Figure 37: I²C EEPROM Connection
4.4 Connecting Three-Wire EEPROMs
µWire EEPROMs and other compatible devices should be connected to the DIO pins DIO4 and DIO5, as
shown in Figure 38 and described below:
• DIO5 connects to both the DI and DO pins of the three-wire device.
• The CS pin must be connected to a vacant DIO pin of the 71M6533/71M6534.
• In order to prevent bus contention, a 10 kΩ to resistor is used to separate the DI and DO signals.
• The CS and CLK pins should be pulled down with a resistor to prevent operation of the three-wire
device on power-up, before the 71M6533/71M6534 can establish a stable signal for CS and CLK.
• The DIO_EEX[1:0] field in I/O RAM must be set to 2 in order to convert the DIO pins DIO4 and DIO5
to µWire pins.
The µ-Wire EEPROM interface is only functional when MPU_DIV[2:0] = 000.
Rev 2
73