emSTAMP Helium (Rev3)
17/23
6
Functional Description of Helium SBC board
As the SBC uses the module as its core all module specifications are also valid for the SBC.
The following section describes the interfaces connected to the outside pins of the module.
6.1
Micro SD-Card
A micro SD-Card socket is available. All signals are directly connected to the processor
module interface SDMMC1 without any further provisions. A write protect signal line is not
provided.
Pin
Signal
1
D2
(PA20)
2
D3
(PA21)
3
CMD
(PA28)
4
VDD
(VDD_SDMMC)
5
CLK
(PA22)
6
GND
7
D0
(PA18)
8
D1
(PA19)
9
CD
(PA30)
10
GND
6.2
Ethernet
A 10/100 MBit Ethernet interface is available via RJ45 connector. The center taps of the
magnetics are connected to a 3.3V DC supply. There no traffic or Link LEDs available.
Pin Signal
1
n/c
2
n/c
3
TD+
(ETH_TDP)
4
TXC
5
TD-
(ETH_TDM)
6
RD+
(ETH_RDP)
7
RXC
8
RD-
(ETH_RDM)
9
n/c
10
GND
11
n/c
12
n/c
6.3
USB 2.0 HOST
A USB2.0 Host interface is provided to connect USB devices such as a keyboard, mouse,
printer or memory stick.
