Specifications

Chapter 3 Hardware
32 Reference Manual CoreModule 720
I
2
C Interface
The CoreModule 720 provides a single-channel I2C interface, which conforms to version 2.1 of the I2C bus
specification. The I2C controller resides on the EG20T PCH and operates as a master or slave device,
supporting a multi-master bus. The following list highlights the features of the I2C bus interface.
♦ Supports delay processing of data read/write operation
♦ Supports master and slave devices
♦ Supports SCL generation when acting as a clock master
♦ Supports multiple masters
♦ Supports Low-Speed BusClock as its clock source and generates an SCL clock based on the set
value of the I2CBC register
♦ Supports 32-byte buffering
♦ Provides a function that generates time out in buffer mode
Table 3-14 defines the pin signals of the I
2
C bus interface, which provides a 5-pin, single-row header with
0.079" (2mm) pitch.
Note: The shaded table cells denote power or ground.
System Fan
Table 3-19 lists the pin signals of the System Fan header, which provides a single row of 3 pins with 0.079"
(2mm) pitch.
Note: The shaded table cells denote power or ground.
Battery
Table 3-20 lists the pin signals of the External Battery Input header for backup CMOS RAM and RTC (Real
Time Clock), which uses 2 pins, in a single row, with 0.049" (1.25mm) pitch.
Note: The shaded table cells denote power or ground.
Table 3-18. I
2
C Interface Pin Signals (J6)
Pin # Signal Description
1 I2C_CLK I2C Clock
2
GND Ground
3 I2C_DATA I2C Data
4
+3.3V +3.3 volts power
5 NC Not Connected
Table 3-19. System Fan Pin Signals (J21)
Pin # Signal Description
1
+V_FAN +5.0 volts DC +/- 5%
2 NC Not Connected
3
GND Ground
Table 3-20. External Battery Input Header (J20)
Pin # Signal Description
1
VBAT_EXT +3.3 volts DC +/- 5%
2
GND Ground