71M6511 Maxim, 71M6511 Datasheet - Page 82

• Manufacturer Part Number: 71M6511
• Description: The 71M6511 and 71M6511H are highly integrated SoCs with an MPU core, RTC, flash, and LCD driver
• Manufacturer: Maxim

Connecting I2C EEPROMs
I2C EEPROMs or other I2C compatible devices should be connected to the DIO pins DIO4 and DIO5, as shown in Figure 33.
Pull-up resistors of roughly 3kΩ to V3P3 should be used for both SCL and SDA signals. The DIO_EEX 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.
Connecting 5V Devices
In general, all pins of the 71M6511 are compatible with external 5V devices. The exceptions are the power supply pins and the
RX pin of the UART (see section Electrical Specifications).
Figure 34 shows how a 5V signal from an external device can be safely interfaced to the RX pin.
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A Maxim Integrated Products Brand
R1 = 100kΩ
V
IN
V3P3
© 2005–2010 Teridian Semiconductor Corporation
Figure 34: Interfacing RX to a 0-5V Signal
71M6511
71M6511
Figure 33: EEPROM Connection
DIO4
DIO4
DIO5
DIO5
RX
3kΩ
3kΩ
Single-Phase Energy Meter IC
71M651X
3kΩ
3kΩ
EEPROM
EEPROM
SCL
SCL
SDA
SDA
71M6511/71M6511H
V3P3
V3P3
DATA SHEET
NOVEMBER 2010
V2.7