Sony Ericsson GR64 사용자 설명서
LZT 123 1834
70
5.19 Burst Transmission (TX_ON)
Pin
Name
Direction Function
35 TX_ON Output
Transmit
indication
Burst transmission is the period during which the GSM transceiver is transmitting RF
signals. TX_ON is an indicator that the module is transmitting.
signals. TX_ON is an indicator that the module is transmitting.
A typical application may use TX_ON to blank adjacent receiver circuitry as a means
of protecting sensitive input stages. TX_ON is active HIGH.
of protecting sensitive input stages. TX_ON is active HIGH.
5.20 Real Time Clock
The real-time clock (RTC) is driven by a 32.768 kHz clock from an internal crystal
oscillator. The clock is divided by 32,768 to generate a clock with a 1 second period
that increments a 29-bit seconds counter. In addition, it can generate interrupts at a
programmed time. The following are the features of RTC:
oscillator. The clock is divided by 32,768 to generate a clock with a 1 second period
that increments a 29-bit seconds counter. In addition, it can generate interrupts at a
programmed time. The following are the features of RTC:
•
17-year time interval with 1 second resolution.
•
Programmed time alarm interrupt
•
Alarm output pin
An RTC alarm can be set by loading an appropriate value into the seconds alarm
register and enabling an interrupt via an AT-command.
register and enabling an interrupt via an AT-command.
The RTC relies on an uninterrupted 1.5 V (nominal) power supply (VRTC), whether the
module is powered off or on. The RTC alarm operates from the VRTC supply, and
therefore utilize 1.5 V logic. Users have the responsibility to provide a backup
battery to provide uninterrupted VRTC function when the module is powered down.
module is powered off or on. The RTC alarm operates from the VRTC supply, and
therefore utilize 1.5 V logic. Users have the responsibility to provide a backup
battery to provide uninterrupted VRTC function when the module is powered down.
RTC Accuracy
Parameter
Condition
Max
Unit
RTC accuracy
Ambient (+25±2°C) operation
52.6
Secs/month
RTC accuracy
Extreme temperatures
65.2
Secs/month