EMAC SoM-250ES, User Manual

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SoM-250ES_User_Manual_v1.40.doc
-8-
Rev 1.4 © 2014 EMAC, Inc.
2.11 I/O Expansion
The Processor used by the SoM-250 provides a number of unused I/O lines. The SoM-250 provides access to
these lines on connector HDR1. This 44-pin dual row header contains GPIO lines, SPI bus, I
2
C bus, A/D lines,
interrupts and power pins. Signal names listed in the table below are the SoM names as defined in the SoM 200
pin specification.
Pin
Signal Pin Signal
1 3.3V 2 3.3V
3 GPIO1 4 GPIO4
5 GPIO2 6 GPIO5
7 GPIO3 8 GPIO6
9 INT0 10 GPIO7
11 INT1 12 GND
13 OSC0 14 GND
15 OSC1 16 GND
17 ADC4 18 GND
19 ADC5 20 GND
21 ADC6 22 GND
23 ADC7 24 GND
25 SPI_MISO 26 GND
27 SPI_MOSI 28 GND
29
31
33
35
37
39
41
43 SPI_CLK
SPI_CS3
SPI_CS1
I2C_DAT
I2C_CLK
*SOM_RSTOUT
5V_VCC
GND 30
32
34
36
38
40
42
44 GND
GND
GND
GND
GND
GND
5V_VCC
GND
2.12 Real-Time Clock
The SoM-250 is equipped with an external batt
ery for backing up the module’s Real-Time Clock (RTC). Drivers to
access the RTC are included in the operating systems. Jumper JB4 should be placed in the ON position in order
to retain system time when powered down.
2.13 Reset
The SoM-250 provides a Reset Button (PB1). Pressing this button will cause the system to reset.