atr0630 ATMEL Corporation, atr0630 Datasheet - Page 13

• Manufacturer Part Number: atr0630
• Description: Antaris4 Single-chip Gps Receiver - Atmel Corporation
• Manufacturer: ATMEL Corporation

3.3.2
3.4
Table 3-6.
4920B–GPS–06/06
Notes:
GPSMODE12
(Reset = PU)
1
1
1
1
0
0
0
0
(2)
(2)
(2)
(2)
Serial I/O Configuration
1. See
2. Leave open
Sensitivity Settings
Serial I/O Configuration
(Reset = PU)
GPSMODE6
Table 3-7
1
1
1
1
0
0
0
0
(2)
(2)
(2)
(2)
to
Table 3-5.
For all GPS receivers the sensitivity depends on the integration time of the GPS signals. There-
fore there is a trade-off between sensitivity and the time to detect the GPS signal (Time to first
fix). The three modes, “Fast Acquisition”, “Normal” and “High Sensitivity”, have a fixed integra-
tion time. The “Normal” mode, recommended for the most applications, is a trade off between
the sensitivity and TTFF. The “Fast Acquisition” mode is optimized for fast acquisition, at the
cost of a lower sensitivity. The “High Sensitivity” mode is optimized for higher sensitivity, at the
cost of longer TTFF. The “Auto” mode adjusts the integration time (sensitivity) automatically
according to the measured signal levels. That means the receiver with this setting has a fast
TTFF at strong signals, a high sensitivity to acquire weak signals but some times at medium sig-
nal level a higher TTFF as the “Normal” mode. These sensitivity settings affect only the startup
performance not the tracking performance.
The ATR0630 features a two-stage I/O-message and protocol-selection procedure for the two
available serial ports. At the first stage, a certain protocol can be enabled or disabled for a given
USART port or the USB port. Selectable protocols are RTCM, NMEA and UBX. At the second
stage, messages can be enabled or disabled for each enabled protocol on each port. In all con-
figurations described below, all protocols are enabled on all ports, but output messages are
enabled in a way that ports appear to communicate at only one protocol. However, each port will
accept any input message in any of the three implemented protocols.
Notes:
Table 3-10 on page
GPSMODE3
(Fixed PU)
(Reset = PD)
GPSMODE5
0
0
1
1
(1)
(1)
(2)
(2)
0
0
0
0
1. Increased back-up current
2. Leave open
1
1
1
1
(2)
(2)
(2)
(2)
GPS Sensitivity Settings
(Reset = PU) Description
GPSMODE2
USART1/USB
(Output Protocol/
Baud Rate (kBaud))
UBX/57.6
UBX/38.4
UBX/19.2
–/Auto
NMEA/19.2
NMEA/4.8
NMEA/9.6
UBX/115.2
14, the messages are described in the ANTARIS4 protocol specification
1
1
0
0
(2)
(2)
Auto mode
Fast mode
Normal mode (Default ROM value)
High sensitivity
USART2
(Output Protocol/
Baud Rate (kBaud)) Messages
NMEA/19.2
NMEA/9.6
NMEA/4.8
–/Auto
UBX/57.6
UBX/19.2
UBX/38.4
NMEA/19.2
ATR0630 [Preliminary]
High
Medium
Low
Off
High
Low
Medium
Debug
(1)
Information Messages
User, Notice, Warning, Error
User, Notice, Warning, Error
User, Notice, Warning, Error
None
User, Notice, Warning, Error
User, Notice, Warning, Error
User, Notice, Warning, Error
All
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