Smart Machine Smart Decision
4.1.5
Operating Mode
Table 4: Power supply and clock state according to operation mode
Mode
VCC
V_BACKUP
Internal LDO
Main clock
RTC clock
Full on
on
on
on
on
on
Sleep
on
on
on
off
on
Backup
on
on
off
off
on
4.1.5.1
Full on Mode
The module will enter full on mode after first power up with factory configuration settings. Power consumption
will vary depending on the amount of satellite acquisitions and numbers of satellites in track. This mode is also
referenced as Full on, Full Powe
r
or Navigation
mode.
Navigation is available and any configuration settings are valid as long as the VCC power supply is active. When
the power supply is off, settings are reset to factory configuration and receiver performs a cold start on next power
up.
4.1.5.2
Sleep Mode
Sleep mode means a low quiescent (440uA type.) power state, non-volatile RTC, and backup RAM block is
powered on. Other internal blocks like digital baseband and RF are internally powered off. The power supply
input VCC shall be kept active all the time, even during sleep mode.
Entering into sleep mode is sent PMTK command through the communication interface by host side.
Waking up from sleep mode is sent any byte through the communication interface by host side.
4.1.6
VCC_RF
VCC_RF is a 2.8V output for external active antenna, if the external active antenna works at 2.8V voltage supply
domain, the user can use the VCC_RF directly. If the antenna’s power supply is not 2.8V, it should be open. For
passive antenna, VCC_RF should be open.
4.2
UART Interface
SIM68R includes two UART (UART and UART1) interface for serial communication. The UART is as NMEA
output and PMTK command input. The receiver (RXD) and transmitter (TXD) side of every port contains a
16-byte FIFO and has 256 bytes URAM. the baud rates are selectable and ranging from 4.8 to 921.6kbps through
CoreBuilder tool. UART can provide the developers signal or message outputs. UART1 is as RTCM input.
For details about CoreBuilder information, please refer to document [2]
SIM68R_Hardware Design_V1.02
17
2013-01-22