WM_PRJ_M12_UGD_001 - 002
18th September 2003
confidential ©
Page :
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This document is the sole and exclusive property of WAVECOM. Not to be distributed or divulged
without prior written agreement.
Ce document est la propriété exclusive de WAVECOM. Il ne peut être communiqué ou divulgué à
des tiers sans son autorisation préalable.
Additional comments on RESET:
The RESET process is activated either by the external RESET signal or by an
internal signal (coming from a RESET generator). This automatic reset is
activated at Power-up.
The modem remains in RESET mode as long as the RESET signal is held low.
This signal should be used only for “emergency” resets
.
A software reset is always preferred to a hardware reset.
2.3.2 Reset sequence
To activate the « emergency » reset sequence, the RESET signal has to be set
to low for 500
µ
s minimum.
As soon as the reset is complete, the AT interface answers « OK » to the
application. For this, the application has to send
AT
↵
.
If the application manages hardware flow control, the AT command can be
sent during the initialisation phase. Another solution is to use the AT+WIND
command to get an unsolicited status from the modem.
For further details, refer to AT commands documentation [1].
RESET mode
I
BB+RF
=20
to 40 mA
EXTERNAL RESET
STATE OF THE MODEM
Modem READY
Min:500
µ
s
Typ: 2 ms
AT answers “OK”
Modem READY
SIM and network dependent
Modem ON
I
BB+RF
<120 mA
without loc update
Figure 8: Reset sequence diagram
2.4 BOOT
The use of this function is reserved to WAVECOM SA.
