Gemalto M2M GmbH MC56 User Manual

Page of 104
MC55/56 Hardware Interface Description 
Confidential / Preliminary 
s
 
MC55/56_hd_v03.00 
Page 52 of 104 
16.08.2005 
3.9.1 
Features supported on first and second serial interface 
ASC0 
•  8-wire serial interface 
•  Includes the data lines /TXD0 and /RXD0, the status lines /RTS0 and /CTS0 and, in 
addition, the modem control lines /DTR0, /DSR0, /DCD0 and /RING0.  
•  It is primarily designed for voice calls, CSD calls, fax calls and GPRS services and for 
controlling the GSM engine with AT commands. Full Multiplex capability allows the 
interface to be partitioned into three virtual channels, yet with CSD and fax services only 
available on the first logical channel. Please note that when the ASC0 interface runs in 
Multiplex mode, ASC1 cannot be used. For more detailed characteristics see [11]. 
•  The /DTR0 signal will only be polled once per second from the internal firmware of 
MC55/56.  
•  The /RING0 signal serves to indicate incoming calls and other types of URCs (Unsolicited 
Result Code). It can also be used to send pulses to the host application, for example to 
wake up the application from power saving state. For further details see Chapter 
3.12.2.3. 
•  Autobauding is only selectable on ASC0 and supports the following bit rates: 1200, 2400, 
4800, 9600, 19200, 38400, 57600, 115200, 230400 bps.  
•  Autobauding is not compatible with multiplex mode, see [11]. 
 
 
ASC1 
•  4-wire serial interface 
•  Includes only the data lines /TXD1 and /RXD1 plus /RTS1 and /CTS1 for hardware 
handshake. This interface is intended for voice calls, GPRS services and for controlling 
the GSM engine with AT commands. It is not suited for CSD calls, fax calls and Multiplex 
mode.  
•  On ASC1 no RING line is available. The indication of URCs on the second interface 
 
 
ASC0 and ASC1 
•  Both interfaces are configured for 8 data bits, no parity and 1 stop bit, and can be 
operated at bit rates from 300bps to 230400 bps.  
•  XON/XOFF software flow control can be used on both interfaces (except if power saving 
is active). 
 
Table 13: DCE-DTE wiring of 1
st
 serial interface 
DCE 
DTE 
V.24 
circuit 
Pin function 
Signal direction 
Pin function 
Signal direction 
103 
/TXD0 
Input 
/TXD 
Output 
104 
/RXD0 
Output 
/RXD 
Input 
105 
/RTS0 
Input 
/RTS 
Output 
106 
/CTS0 
Output 
/CTS 
Input 
108/2 
/DTR0 
Input 
/DTR 
Output 
107 
/DSR0 
Output 
/DSR 
Input 
109 
/DCD0 
Output 
/DCD 
Input 
125 
/RING0 
Output 
/RING 
Input