User guide

CobraNet Programmer’s Reference

Overview

1. Overview

1.1 CobraNet Terminology

CobraNet is a technology that combines state of the art audio and communications

technologies. While each have their own terminology, the following terms are used to refer

to elements specific to CobraNet.

Audio Channel—A CobraNet digital audio channel operates with a sample rate 48 kHz

or 96 kHz and a sample size of 16, 20, or 24 bits.

Bundle—A Bundle* is the basic CobraNet audio routing element and can carry 0 to 8

audio channels. Bundles are assigned a number which determines both which interface

the Bundle is routed to and in what manner. The range within which the Bundle number

falls determines whether it is routed as a multicast, unicast, or private type. Bundles are

numbered 1 through 65535. CobraNet interfaces are capable of sending and receiving

multiple bundles simultaneously. Bundle numbers are described in more detail in Table 2.,

"Bundle Numbering" .

Bundles were formerly referred to as channels or network channels and may be seen represented as such in some SNMP

variable names and older documentation.

CobraNet Device—A CobraNet device is any equipment containing one or more

CobraNet interfaces.

CobraNet Interface—The CobraNet interface is the hardware (or hardware design) and

software supplied by Cirrus Logic to manufacturers of CobraNet enabled equipment.

Several generations of the CobraNet interface exist and will interoperate with each other:

CS4961xx and CS1810xx - A family of CobraNet chips containing one or more

32-bit, 120-MIPS DSP cores, RAM and audio I/O circuitry.

CM-2 - A modular CobraNet interface based on a CS4961xx device.

CM-1 - A modular CobraNet interface based on a 24-bit, 100 MIPS DSP.

Silicon Series Reference Design - A CobraNet design based on the CS1810xx

or CS4961xx. This is essentially a CM-2 without the modular circuit board and

host interface connector.

24-bit Platform - CobraNet interfaces based on 24-bit DSPs: Reference design,

CM-1.

32-bit Platform - CobraNet interfaces based on 32-bit DSPs: CS4961xx and

CS1810xx, CM-2.

Reference Design - A CobraNet interface design based on a 24-bit, 40 MIPS

DSP.

Conductor—The conductor is the CobraNet interface elected to provide master clock

and transmission arbitration for the network. The role of the conductor and the means for

selecting a conductor are described elsewhere in this document. All CobraNet devices

other than the conductor operate in a performer role.

Isochronous cycle - One or more CobraNet bundles are transmitted each isochronous

cycle. The period of an isochronous cycle is 750 Hz or 1-1/3 mS