Specifications

WA_DEV_FEX20_PTS_004 Rev 001 June 30, 2010 27
Expansion Card Product Technical
Specification
Interfaces
Signal
Description
Minimum
Typical
Maximum
Unit
T-stop
Setup time STOP condition
0.6
µs
T-free
Bus free time, STOP to START
1.3
µs
T-high
High period for clock
0.6
µs
T-data-hold
Data hold time
0
0.9
µs
T-data-setup
Data setup time
100
ns
4.5. Auxiliary Serial Link (UART2)
GPS or Bluetooth applications can be interfaced on the auxiliary serial link (UART2).
4.5.1. Pin Description
Refer to the following table for the pin description of the UART2 interface.
Table 18: UART2 Pin Description
Pin
Number
Signal
I/O
I/O Type
Reset State
Description
Multiplexed
With
24
CT103 / TXD2*
I
1V8
Z
Transmit serial data
GPIO14
23
CT104 / RXD2*
O
1V8
Z
Receive serial data
GPIO15
25
~CT106 / CTS2*
O
1V8
Z
Clear To Send
GPIO16
26
~CT105 / RTS2*
I
1V8
Z
Request To Send
GPIO17
* According to PC view
Refer to section 4.2 Electrical Information for Digital I/O for open drain, 2V8 and 1V8 voltage
characteristics and reset state definitions.
The maximum baud rate of UART2 is 920Kbit/s.
Tip: The Fastrack Xtend is designed to operate using all serial interface signals and it is mandatory to use
RTS2 and CTS2 for hardware flow control in order to avoid data corruption during transmission.
4.6. RF Interface
This interface allows an MMCX connector to be connected to the Expansion Card and has a 50Ω
nominal impedance. Depending on the application used, this can be used for GPS, Bluetooth or other
RF devices.
4.6.1. External Active Antenna Specifications
Typically, if active antennas are used (GPS, for example), a DC supply is applied through the RF
connector. The table below describes the common characteristics of a GPS external antenna.