ISDN Data and Telephony Protocol Engine (inc. X.25)
CMX228
1.6
Application Notes
1.6.1 General
The CMX228 is intended for use as part of an ISDN chipset. The CML recommended hardware
implementation contains the following elements (refer to Figure 3):
‘S’ bus interface via RJ45 socket.
RJ11 analogue telephone socket and analogue circuitry.
ISDN line transformer.
AMD79C30 S-interface controller.
Single asynchronous RS232 interface via 9-way or 25-way D-type connector.
64K bytes external RAM.
16K Non-volatile memory.
Ten processor controlled LED indicator signals.
HDLC drivers for the 2 ISDN B-channels, both channels can be used for data transfer.
Figure 3 Application Block Diagram
1.6.2 Approvals
The firmware and finite state machine embedded in the CMX228 have been used in products which
have gained ETSI CTR3 approval.
ã 1999 Consumer Microcircuits Limited
ã 1999 Chiron Technology Limited
31
D/228/1
CMLMICRO [ CML MICROCIRCUITS ]
