User's Manual
Table Of Contents
- Contents
- Figures
- Tables
- Document History
- Introduction
- Product concept
- Application Interface
- Antenna interface
- Electrical, reliability and radio characteristics
- Mechanics
- Reference Approval
- List of parts and accessories
MC46 Hardware Interface Description
DRAFT
MC46_HD_V02.8xb Page 61 of 98 21.08.2003
1s
/
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 (see also chapter 3.9). 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 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.
Figure 24: Incoming voice call
· Likewise, when a Fax or data call is received, /RING0 goes low. However, in contrast to
voice calls, the line remains low. Every 5 seconds the ring string is generated and sent
over the /RXD0 line.
Figure 25: Incoming data call
· All types of Unsolicited Result Codes (URCs) also cause the
/RING0 line to go low, however for 1 second only.
For example, MC46 may be configured to output a URC
upon the receipt of an SMS. As a result, if this URC type
was activated with AT+CNMI=1,1, each incoming SMS
causes the /RING0 line to go low. See [1] for detailed
information on URCs.
Figure 26: URC transmission
4s
/RING0
4s
1s
1s
1s
Ring
string
Ring
string
Ring
string
5s
/RING0
Ring
string
Ring
string
Ring
string
5s