CMX228S1 MX-COM, Inc., CMX228S1 Datasheet - Page 24

• Manufacturer Part Number: CMX228S1
• Description: ISDN data and telephony protocol engine with x.25
• Manufacturer: MX-COM, Inc.

ISDN Data and Telephony Protocol Engine with x.25
4.7
4.7.1
All incoming data calls which have valid channel use and MSN are directed to the data port and cause ‘RING’
followed by the digits of the calling party number and the calling party sub-address (if received in the SETUP
message) to be returned to the DTE. The Ring Indicator (RI) pin is also raised, and then lowered after 3s.
‘RING’ text and the raising of RI for 3s is repeated every 6s until the call is cleared or answered, provided
S0=0. If S0=1 then only one RING will appear at the DTE and the RI line will be raised only once, as a
CONNECT message will be sent to the network.
4.7.2
Outgoing calls are requested specifying either B-channel unless channel mapping is enabled via !C4 and !C5
registers. The SETUP message is sent without High Layer Compatibility or Low Layer Compatibility and with
the following Bearer Capability:
If there is a saved MSN in !C6 register all outgoing call SETUP messages will contain the saved number in a
Calling Party Number Information Element.
4.7.3
When D-channel data is selected (via Hayes register %A2), B-channel data calls cannot be made. Any
incoming B-channel data calls will be rejected with ‘Busy’.
4.7.4
Once a call is connected to the digital port, whether it was incoming or outgoing, the DCD pin is set high to
indicate that the call is connected (providing &C0 command is not given). If the DCD pin is set high, the LED3
pin will be set low.
4.7.5
The call is cleared either by the ATH command or by the ISDN network. When the call has been cleared, the
DCD pin is set low and the LED3 pin is set high (providing the &C0 command is not given).
4.8
Details of this will be supplied to customers under a Non-Disclosure Agreement.
The following Memory Map indicates the main code areas used on the CMX228:
MX-COM, Inc
4800 Bethania Station Road, Winston-Salem, NC, 27105-1201, USA
www.mxcom.com tel: [phone] 744 5050 fax: [phone]
All trademarks and service marks are held by their respective companies
CCITT coding standard
Unrestricted digital
Circuit mode
64k information transfer rate
Data Operation
Incoming B-Channel Data Calls
Outgoing B-Channel Data Calls
X.25 Data Calls on the D-Channel
Connected Calls
Call Clearing
Application Programmer's Interface
Function
Code Space
External RAM
API area
AMD79C30 ISDN Interface Chip
PSB21525 HDLC Driver Chip
Reserved
Start Hex Address
24
0C0 000
0F0 000
0F0 100
0F0 200
000 000
020 000
End Hex Address
03F FFF
0EF FFF
0FF FFF
01F FFF
0F0 0FF
0F0 1FF
2000 Chiron Technology Limited
CMX228 Advance Information
Doc. # 20480216.001
2000 MX-COM, Inc.