User's Manual

Table Of Contents
33 novatelwireless.com
The 16 bit word is sent MSB first. Data received is also MSB first. No other data manipulation is
done within the module.
Pin Name Pin Number Signal Direction Description
MCSI_RX 12 I Serial Data Input
MCSI_TX 18 O Serial Data Output
MCSI_CLK 14 IO Serial Clock I/O
MCSI_FSYNC 16 IO Frame Synchronization I/O
VBackup Input (Pin83)
The backup battery can be recharged from the main battery. A programmable voltage
regulator powered by the main battery allows recharging the backup battery. The backup
battery charge starts when the following conditions are met:
Backup battery charge is enabled by a control bit:
l
Main Battery voltage > Backup Battery voltage
l
Main battery > 2.8 Vdc
Note: If the backup battery is not present, the backup battery pin is connected to
main battery pin
VBACKUP is a power input for the Real-Time-Clock when using RTC-Sleep Function
VBACKUP Parameter/Conditions Min Typ Max Units
Input Voltage Range ON mode 2.5 VCC1 5.5 Vdc
BACKUP mode, VBAT=0v 1.9 VBACKUP 5.5
BACKUP mode, VBACKUP=0v 1.9 VCC2 3.0
Input Current 10 mA
Using VBackup
VBACKUP is a backup voltage that can maintain the RTC clock and alarm functions. If
VBACKUP is not present in the system (intentionally or not) the RTC clock may still be
powered if leakage voltage exists on VCC. Otherwise, the RTC clock will lose power and be
reset when VCC is restored.
PARAMETER Parameter/Conditions Min Typ Max Units