Multitech MT-SMI-DK Development Manual page 13

CHAPTER 2 – UNIVERSAL SOCKET PINOUT
Pin Signal Name
10 Unused
11 Unused
12 Unused
13 Unused
14 Unused
15 GPS-SDI
16 GPS-SDO
17 GPS-PPS
18 SPI_CLK
19 SPI_MISO
20 SPI_MOSI
21 SPI_CS0
22 MIC+
23 MIC-
24 -RESET*
25 USB_VBUS
26 GND
27 USB_DP
28 USB_DN
29 LED DCD
30 LED RX
31 LED DTR
32 LED TX
33 –RTS
13
In/Out Description
N/A Reserved for future use.
N/A Reserved for future use.
N/A Reserved for future use.
N/A Reserved for future use.
N/A Reserved for future use.
I GPS Data In.
O GPS Data Out.
GPS Pulse per Second.
Serial Peripheral Interface custom factory option.
O Serial Peripheral Interface custom factory option.
I Serial Peripheral Interface custom factory option.
Serial Peripheral Interface custom factory option.
I Microphone positive input. See individual Device Guides for microphone details.
I Microphone negative input. See individual Device Guides for microphone details.
I Device Reset (with pull-up). The active low –RESET input resets the device logic
and returns the configuration of the device to the original factory default values or
"stored values" in the NVRAM. –RESET is tied to VCC through a time-constant
circuit for "Power-on-Reset" functionality. See individual Device Guides for
timings.
A Design Consideration
Allowing the host processor to control the SocketModem's RESET line allows the
host to reset the device if it fails to respond normally. Resetting the SocketModem
returns it to a known functional state.
I USB Voltage Sense. Senses the voltage level of the USB to determine if the bus is
available.
GND Logic Ground.
I/O USB Data Positive. Positive pin of the USB data pair.
I/O USB Data Negative. Negative pin of the USB data pair.
O DCD (Active High). Output from 74LCX14 with a 1000 Ohms resistor in series.
SocketWireless Bluetooth (MTS2BTSMI): When lit, indicates a connection. No
series resistor.
O RX (Active High). Output from 74LCX14 with a 1000 Ohms resistor in series.
SocketWireless Bluetooth (MTS2BTSMI): No series resistor.
O DTR (Active High). Output from 74LCX14 with a 1000 Ohms resistor in series.
SocketWireless Bluetooth (MTS2BTSMI): No series resistor.
O TX (Active High). Output from 74LCX14 with a 1000 Ohms resistor in series.
SocketWireless Bluetooth (MTS2BTSMI): No series resistor.
I Request to Send (Active Low). –RTS is controlled by the DTE to indicate whether
or not the DTE is ready to receive data. –RTS ON (low) indicates that the DTE is
ready to receive data from the modem on RXD. –RTS OFF indicates to the
SocketModem that it should not transfer data on the RXD.
When the –RTS pin is not in use, it should be tied low.
Note:
Universal Socket Developer Guide