Gemalto M2M GmbH MC56 User Manual
MC55/56 Hardware Interface Description
Confidential / Preliminary
Confidential / Preliminary
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MC55/56_hd_v03.00
Page 65 of 104
16.08.2005
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/RING0
URC
3.12.2.3 Behavior of the /RING0 line (ASC0 interface only)
The /RING0 line is available on the first serial interface (ASC0). The signal serves to indicate
incoming calls and other types of URCs (Unsolicited Result Code).
Although not mandatory for use in a host application, it is strongly suggested that you
connect the /RING0 line to an interrupt line of your application. In this case, the application
can be designed to receive an interrupt when a falling edge on /RING0 occurs. This solution
is most effective, particularly, for waking up an application from power saving. Note that if the
/RING0 line is not wired, the application would be required to permanently poll the data and
status lines of the serial interface at the expense of a higher current consumption. Therefore,
utilizing the /RING0 line provides an option to significantly reduce the overall current
consumption of your application.
The behavior of the /RING0 line varies with the type of event:
• When a voice/fax/data call comes in the /RING0 line goes low for 1s and high for another
incoming calls and other types of URCs (Unsolicited Result Code).
Although not mandatory for use in a host application, it is strongly suggested that you
connect the /RING0 line to an interrupt line of your application. In this case, the application
can be designed to receive an interrupt when a falling edge on /RING0 occurs. This solution
is most effective, particularly, for waking up an application from power saving. Note that if the
/RING0 line is not wired, the application would be required to permanently poll the data and
status lines of the serial interface at the expense of a higher current consumption. Therefore,
utilizing the /RING0 line provides an option to significantly reduce the overall current
consumption of your application.
The behavior of the /RING0 line varies with the type of event:
• When a voice/fax/data call comes in the /RING0 line goes low for 1s and high for another
4s. Every 5 seconds the ring string is generated and sent over the /RXD0 line.
If there is a call in progress and call waiting is activated for a connected handset or
handsfree device, the /RING0 line switches to ground in order to generate acoustic
signals that indicate the waiting call.
If there is a call in progress and call waiting is activated for a connected handset or
handsfree device, the /RING0 line switches to ground in order to generate acoustic
signals that indicate the waiting call.
Figure 24: Incoming voice call
• All other types of Unsolicited Result Codes (URCs) also
cause the /RING0 line to go low, however for 1 second only.
Figure 25: URC transmission
Table 19: ASC0 ring signal
Function
Pin
Status Description
0
Indicates an incoming call or URC. If in NON-CYCLIC
SLEEP mode CFUN=0 or CYCLIC SLEEP mode
CFUN=5 or 6, the module is caused to wake up to full
functionality. If CFUN=7 or 8, power saving is resumed
after URC transmission or end of call.
SLEEP mode CFUN=0 or CYCLIC SLEEP mode
CFUN=5 or 6, the module is caused to wake up to full
functionality. If CFUN=7 or 8, power saving is resumed
after URC transmission or end of call.
Ring indication
GSM_RING0
1
No operation
4s
/RING0
4s
1s
1s
1s
Ring
string
Ring
string
Ring
string