MC145574AAC Freescale Semiconductor, MC145574AAC Datasheet - Page 47

• Manufacturer Part Number: MC145574AAC
• Description: IC TRANSCEIVER ISDN 32-LQFP
• Manufacturer: Freescale Semiconductor
• Type: Transceiverr

Specifications of MC145574AAC

• Voltage - Supply: 4.75 V ~ 5.25 V
• Mounting Type: Surface Mount
• Package / Case: 32-LQFP
• Number Of Line Interfaces: 1
• Control Interface: HDLC
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Number Of Drivers/receivers: -
• Protocol: -
• Lead Free Status / Rohs Status: Compliant

MOTOROLA
6.1
6.2
6.3
OVERVIEW
The MC145574 is able to work with a General Circuit Interface port (GCI). The GCI is a standard
four–wire interface between devices for the subscriber access in ISDN and analog environments. The
principle use in these applications is to control the subscriber line interface circuitry.
The following are some of the benefits of the General Circuit Interface.
The GCI interface consists of a transmit path, a receive path, an associated clock, and a frame sync
signal. These signals are known as D out , D in , DCL, and FSC.
The clock determines the rate of exchange of data in both the transmit and receive directions. The
frame sync signal indicates when this exchange will start.
GCI FRAME STRUCTURE
In a GCI channel, information is in a 4–byte time–division based structure with a repetition rate of
8 kHz. The four bytes are B1 and B2 channels, a monitor (M) channel, and a C/I channel.
The two independent B channels are used to carry subscriber voice and data information. The M chan-
nel is used for operation and maintenance facilities. The C/I channel is further subdivided into two
bits for the D channel information, four bits for the control/indication (C/I) channel, and two bits for
the A and E channels that are used to control the transfer of information on the Monitor channel.
Figure 6–1 shows the relative positions of these channels.
ENABLING THE GCI MODES
GCI modes can be enabled via two different methods, depending on the application requirements.
1. The GCI mode can be enabled through the GCI control register present in the SCP. This is called
2. Alternatively, if the SCP port is not required or available, then the GCI mode can be enabled at
Operation and Maintenance Features
Activation and Deactivation Facilities (via a Control Indication (C/I) Channel)
Well–Defined Transmission Protocols to Ensure Correct Information Transfer Between GCI Com-
patible Devices
Point–to–Point and Multipoint Communication Links
Multiplexed Mode of Operation Where up to Eight GCI Channels can be Combined to Form a
Single Data Stream
indirect mode. See descriptions for OR6(2) and OR5.
hardware reset. This is called direct mode. This is done by connecting SCPEN/GCIEN to V SS
during reset.
Freescale Semiconductor, Inc.
For More Information On This Product,
Go to: www.freescale.com
GENERAL CIRCUIT INTERFACE
MC145574
6
6–1