CN8478/CN8474A/CN8472A/CN8471A
8.0 Terms, Definitions, and Conventions
Multichannel Synchronous Communications Controller (MUSYCC™)
8.6 Definitions
8.6 Definitions
bit field
Any group of associated information bits that must always be viewed together to
provide the desired information. For example, in a 3-bit field, the 3 bits can
represent 8 related values and thus must always be viewed together.
byte
A field made up of 8 binary bits.
channel
A logical bit stream through MUSYCC. A channel has an associated transmit and
receive direction. The transmit direction is for the bit stream flowing from shared
memory towards the serial port. The receive direction is for the bit stream flowing
from the serial port to the shared memory. A channel within MUSYCC is
bidirectional. The rate of data flow is configurable and is specified in bits per
second.
channelized
A serial port configuration whereby a higher speed bit stream is partitioned into
lower speed bit streams or time slots. A frame synchronization signal is required
and allows mapping of individual bits within the time slots into logical channels.
This term is synonymous with PCM Highway.
channel group
data buffer
MUSYCC is designed around four independent and full-duplexed sets of
channels. Each channel group supports up to 32 logical channels.
A block of shared memory where data messages are stored. As messages are
received from the serial port, MUSYCC writes the message to shared memory
data buffers. As messages are sent out on the serial port, MUSYCC takes
messages from shared memory data buffers.
descriptor
dword
A data structure used to specify attributes of a separate block of data.
A field consisting of 32 binary bits, or 2 words concatenated, or 4 bytes
concatenated.
FIFO
A region of memory designed to facilitate the movement of bits of information in
a first-in-first-out manner.
flag
As defined by HDLC protocol, an octet with the value 7Eh (01111110b).
frame
In the context of an HDLC bit stream, this term is synonymous with message and
packet. In terms of a serial interface, a frame is a grouping of synchronous bits
relative to a serial line clock and delimited by a synchronization signal. The frame
structure is defined by the physical interface providing the framed data.
hyperchannel
idle code
Concatenation of time slots into a single logical channel. The available bandwidth
for such a logical channel is the sum of bandwidth of each time slot.
An octet pattern used to fill the time between the closing flag of one message and the
opening flag of the subsequent message. The following idles codes are supported:
7Eh, FFh, and 00h.
100660E
Conexant
8-7
CONEXANT [ CONEXANT SYSTEMS, INC ]
