Datasheet

78M6612 Data Sheet DS_6612_001
24 Rev 2
3.7 Connecting Three-Wire EEPROMs
µWire EEPROMs and other compatible devices should be connected to the DIO pins DIO4 and DIO5, as
shown in Figure 13 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 78M6618.
• 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 resistors to prevent operation of the three-wire
device on power-up, before the 78M6618 can establish a stable signal for CS and CLK.
• The DIO_EEX register in I/O RAM must be set to 2 (b10) 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.
Figure 13: Three-Wire EEPROM Connection
3.8 UART0 (TX0/RX0)
The UART0 RX0 pin should be pulled down by a 10 kΩ resistor and additionally protected by a 100 pF
ceramic capacitor, as shown in Figure 14.
Figure 14: Connections for the RX0 Pin
TX0
RX0
10k
Ω
100pF
RX
TX
78M6612
10k
Ω
100pF
RX0
TX0
DIO4
DIO5
EEPROM
SCLK
DI
V3P3D
10k
Ω
CS
DIOn
DO
10k
Ω
DIO4
DIO5
78M6612
EEPROM
SCLK
DI
V3P3D
10k
Ω
CS
DIOn
DO
10k
Ω