ATR0621 Datasheet, PDF (10/20 Pages) ATMEL Corporation – GPS Baseband Processor

3.3 Setting GPSMODE0 to GPSMODE12
The start-up configuration of a ROM-based system without external non-volatile memory is
defined by the status of the GPSMODE pins after system reset. Alternatively, the system can
be configured through message commands passed through the serial interface after start-up.
If Flash memory is available, configuration data can be stored in Flash memory. If EEPROM
memory is connected, configuration data can be stored in EEPROM. Default designates set-
tings used by ROM firmware if GPSMODE configuration is disabled (GPSMODE0 =0).
3.3.1
3.3.2
Table 3-3. GPSMODE Functions
Pin
Function
GPSMODE0
Enable configuration with GPSMODE pins
GPSMODE1
This pin is used for FixNow functionality and not used for GPSMODE configuration
GPSMODE2
GPSMODE3
GPS sensitivity settings
GPSMODE4
This pin (NAADET1) is used as active antenna supervisor input and not used for
GPSMODE configuration
GPSMODE5
GPSMODE6
Serial I/O configuration
GPSMODE7
USB Power Mode
GPSMODE8
General I/O Configuration
GPSMODE9
This pin (NAADET0) is used as active antenna supervisor input and not used for
GPSMODE configuration
GPSMODE10
GPSMODE11
General I/O Configuration
GPSMODE12
Serial I/O configuration
Enable GPSMODE Pin Configuration
Table 3-4. Enable Configuration with GPSMODE Pins
GPSMODE0
(Reset = PD) Description
0
Ignore all GPSMODE pins. The default settings as indicated below are used
1
Use settings as specified with GPSMODE[2, 3, 5 to 8, 10 to12]
Sensitivity Settings
Table 3-5. GPS Sensitivity Settings
GPSMODE3 GPSMODE2
(Fixed PU) (Reset = PU) Description
0
0
Auto mode
0
1
Fast mode
1
0
Normal mode (Default)
1
1
High sensitivity
10 ATR0621 [Preliminary]
4890AS–GPS–09/05