User`s manual

V1.2 – May-11 User’s Manual Page 16 of 37
antenna input of the module) should not exceed 30 dB. The noise figure should be ≤
1.5dB.
3.3 Serial Port Settings
In UART operation (defined by the external pull-up resistor as outlined in Minimum
Configuration) the default settings are:
• NMEA, 4800 baud, 8 data bits, no parity, 1 stop bit, no flow control
3.4 Improved TTFF
In order to improve the TTFF (Time To First Fix), it is recommended to keep Vcc
supplied at all times. This will allow taking advantage of sophisticated low power
mode features of the SiRFstarIV chip set. More details can be found in chapter
“Application Notes”.
3.5 Firmware Updates
If later firmware changes are considered in a design it is necessary to connect the
BOOTSEL pin of the A2100-A/B. As long as this pin is open or pulled to GND, the
module will enter normal operation. When this pin is pulled HIGH to a 1.8V level the
module will enter boot mode. A transparent connection to the tool SiRFflash then
allows firmware updates.