Datasheet

FDS_6533_6534_004 71M6533/G/H and 71M6534/H Data Sheet
Rev 2 73
Figure 36: Connecting LCDs
4.3 Connecting I
2
C EEPROMs
I
2
C EEPROMs or other I
2
C 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 I
2
C pins SCL and SDA.
Figure 37: I
2
C 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.
DIO4
DIO5
EEPROM
SCL
SDA
V3P3D
10 k
Ω
10 k
Ω
segments
LCD
commons
71M6533/71M6534
71M6533/71M6534