RISC Microcode from RAM
MC68360 USER’S MANUAL
C.2 MULTIPLE GCI CONTROLLER
The MC68360 Quad Integrated Communications Controller (QUICC) can handle connec-
tions over two basic rate ISDN links using its Serial Management Controllers. For connection
to more than two ISDN links, the Multiple GCI (MGCI) RAM-based microcode provides Gen-
eral Circuit Interface (GCI) handling functions for up to 16 basic rate ISDN subscriber lines.
MGCI can be used in any application where multiple ISDN lines need to be terminated, such
as 2, 4, 8, or 16-subscriber ISDN line cards and video servers.
Associated with each ISDN subscriber line is a monitor channel, a C/I channel, two B-chan-
nels, and one D-channel. MGCI handles only the monitor and C/I channels and has no effect
on the B and D channels.
C.2.1 Typical Application
Figure C-1 shows a typical 16-subscriber ISDN line card using MGCI in an ISDN switch.
Each subscriber line is terminated on the line card by a U or S/T line transceiver (e.g.
MC145572 or MC145574). The multiplexer logic converts between the 16 individual basic
rate GCI circuits and time division multiplex links carrying the D, B and control channels. The
B channels are routed to the main system via the system interface while the D-channels are
handled on the board. The C/I and monitor channels are used on the board to carry control
and status information between the MC68360 and the line transceivers.
C.2.2 MGCI Controller Key Features
Implements ISDN GCI and analog GCI monitor channel and C/I channel protocols.
Handles GCI monitor message reception and transmission automatically.
Handles four and six bit C/I code reception and transmission.
User programmable C/I receiver detection mechanism: single change or double last
look.
Figure C-1. Typical 16-SUbscriber ISDN Line
D-Channel
Signalling
Controller
MC68360
QUICC
Address
& Data
UART
TDMA
TDMB
Memory
Multiplexer
System
Interface
MC145572
Subscriber
Interfaces
System
Backplane
16
D
16
C/I + M
3
HDLC
16
2B
16
2B+D+C/I+M
GCI
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Freescale Semiconductor, Inc.
For More Information On This Product,
Go to: www.freescale.com
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