CN8478 Datasheet, PDF (80/221 Pages) Conexant Systems, Inc – Multichannel Synchronous Communications Controller (MUSYCC)

4.0 Serial Interface
4.6 Serial Port Mapping
CN8478/CN8474A/CN8472A/CN8471A
Multichannel Synchronous Communications Controller (MUSYCC™)
The following port mappings are available:
• PORTMAP = 0, 1x port mode
Default mode after device reset. Each serial port is logically connected to
one channel group, and each port terminates up to 32 bidirectional
channels.
• PORTMAP = 1, 2x port mode
Each of two serial ports is logically connected to two channel groups. In
this mode, serial port 0 is connected to channel groups 0 and 1, serial port
1 is connected to channel groups 2 and 3, serial port 2 is connected to
channel group 4 and 5, and serial port 3 is connected to channel group 6
and 7. Each serial port terminates up to 64 bidirectional channels.
• PORTMAP = 2, 4x port mode
Serial port 0 is logically connected to channel groups 0, 1, 2, and 3, and
serial port 1 is logically connected to channel groups 4, 5, 6, and 7. Serial
ports 2 through 7 are disabled.
Mapping a serial port to one or more logical channels in a channel group is one
element of serial port configuration; another is indicating the channelized data
rate of the serial interface, accomplished by configuring the PORTMAP bit field
(Table 5-6, Global Configuration Descriptor). The connection between the serial
port and the physical layer interface indicates the relationship to physical layer
time slots.
Each serial port can be configured to support 24, 32, 64, 128 or a variable
number of 8-bit time slots up to 128. Each serial port can be configured to
support data rates up to and including 8.192 Mbps. Also, each serial port can be
independently wired to a separate source of serial data, or all four serial ports can
be wired to a single source of serial data.
4-10
Conexant
100660E