Software Design; Power Down Control; Timing And Operation; Main Modes Of Operation - Ericsson EF738 Service Manual

Software Design

Power Down Control

All voltage regulators are on all the time when in SLEEP, STAND BY and TRANS-
MIT mode. The operation modes of ANTON and BERTINDY are software control-
led directly from GUSTAV through the serial interface.

Timing and Operation

In the ETACS system it is most important that a well working sleep function can be
implemented as this will increase the standby time by several hours.

Main Modes of Operation

The transceiver hardware operation can be split into four main modes: OFF, SLEEP,
STAND BY and TRANSMIT.
• OFF is when all regulated power are switched off by the on/off logic. The hard-
• SLEEP mode is the lowest operation mode the transceiver can be put in (excl.
• STAND BY mode is the normal data receive mode, where the transceiver can
• TRANSMIT mode is the normal conversation/data mode.

Power Saving Sleep Function

When in STAND BY mode the transceiver doesn't have to be awake listening all
the time as there are time slots where the transceiver can be put into SLEEP mode.

Software Assignments

Software is loaded via the serial channel through GUSTAV into the Flash EPROM
and the main assignments are:
• controller of the hardware circuitry
• communicator with the cellular system via the RF link
• provider and handler of the operating interface to the user
• provider of test and tune commands for factory and field service
• co-ordinator of the overall system (e.g. operating system)
• controller of the battery charging
ware is powered up when the voltage regulators are enabled. At power-up the
8 MHz clock frequency synthesizer has to be loaded with the correct division
ratios and the RAM has to loaded as well. All software controlled circuits have
to be initiated and loaded with their default settings, and then powered down by
software until needed again.
OFF mode). All receiver, transmitter and audio circuits are put in power down
mode or switched off.
listen to the data signalling from the base station.
Technical Description
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