Gemalto M2M GmbH MC56 User Manual
MC55/56 Hardware Interface Description
Confidential / Preliminary
Confidential / Preliminary
s
MC55/56_hd_v03.00
Page 29 of 104
16.08.2005
Assertion of CTS indicates that the module is ready to receive data from the host application.
In addition, if configured to a fixed bit rate (AT+IPR≠0), the module will send the URC
“^SYSSTART” which notifies the host application that the first AT command can be sent to
the module. The duration until this URC is output varies with the SIM card and may take a
couple of seconds, particularly if the request for the SIM PIN is deactivated on the SIM card.
Please note that no “^SYSSTART” URC will be generated if autobauding (AT+IPR=0) is
enabled.
To allow the application to detect the ready state of the module we recommend using
hardware flow control which can be set with AT\Q or AT+ICF (see [1] for details). The default
setting of MC55/56 is AT\Q0 (no flow control) which shall be altered to AT\Q3 (RTS/CTS
handshake). If the application design does not integrate RTS/CTS lines the host application
shall wait at least for the “^SYSSTART” URC. However, if the URCs are neither used (due to
autobauding) then the only way of checking the module’s ready state is polling. To do so, try
to send characters (e.g. “at”) until the module is responding.
In addition, if configured to a fixed bit rate (AT+IPR≠0), the module will send the URC
“^SYSSTART” which notifies the host application that the first AT command can be sent to
the module. The duration until this URC is output varies with the SIM card and may take a
couple of seconds, particularly if the request for the SIM PIN is deactivated on the SIM card.
Please note that no “^SYSSTART” URC will be generated if autobauding (AT+IPR=0) is
enabled.
To allow the application to detect the ready state of the module we recommend using
hardware flow control which can be set with AT\Q or AT+ICF (see [1] for details). The default
setting of MC55/56 is AT\Q0 (no flow control) which shall be altered to AT\Q3 (RTS/CTS
handshake). If the application design does not integrate RTS/CTS lines the host application
shall wait at least for the “^SYSSTART” URC. However, if the URCs are neither used (due to
autobauding) then the only way of checking the module’s ready state is polling. To do so, try
to send characters (e.g. “at”) until the module is responding.
3.3.1.2
Timing of the ignition process
When designing your application platform take into account that powering up MC55/56
requires the following steps.
• The ignition line cannot be operated until V
requires the following steps.
• The ignition line cannot be operated until V
BATT+
passes the level of 3.0V.
• The ignition line shall not be operated earlier than 10ms after the last falling edge of VDD.
• 10ms after V
BATT+
has reached 3.0V the ignition line can be switched low. The duration of
the falling edge must not exceed 1ms.
• Another 100ms are required to power up the module.
• Ensure that V
• Ensure that V
BATT+
does not fall below 3.0V while the ignition line is driven. Otherwise the
module cannot be activated.
• If the VDDLP line is fed from an external power supply as explained in Chapter 3.8, the
/IGT line is HiZ before the rising edge of BATT+.
Figure 4: Timing of power-on process if VDDLP is not used
3.0V
0V
BATT+
min. 100ms
max. 1ms
10ms
/IGT
HiZ
HiZ