Cirrus Logic AN334 User Manual
AN334
CS1810xx / CS4961xx Bring-up Instructions
1. INTRODUCTION
CobraNet® firmware is stored in external FLASH memory which must be programmed before the CobraNet device
can become operational.
Once an initial firmware load of the FLASH is accomplished, the device will be functional. All subsequent firmware
updates can be accomplished via the network, using Cirrus-supplied tools such as CobraNet Discovery or the Python-based manufacturing script.
There are two means for accomplishing this initial firmware load:
• Use of pre-programmed FLASH
• Use of the CID debug interface tool
1.1 Pre-Programmed Flash Device
The simplest and most efficient approach, especially for volume production, is to pre-program the FLASH
memory before it is soldered to the circuit board.
CobraNet firmware is delivered as a 1M byte binary file (example: cm18101_2_11_6.bin). The latest firmware may be downloaded from th e C irr us L og i c w eb site at htt p://www.cirrus.com. The firmware binary file
is an exact image of FLASH contents required to boot and operate the CobraNet chip.
A properly constructed CobraNet interface populated with a pre-programmed FLASH will, without intervention, boot and function properly from initial power-up.
It is recommended that the initial firmware image to be used is the cs18100_2_11.x.bin firmware file. This
is the lowest common denominator firmware and will provide proper network functionality in ALL CobraNetchip-based platforms. A manufacturer can then stock only one pre-programmed chip type and then, later,
update specifically required firmware variants during the manufacturing process. FLASH will always need
to be reprogrammed in any case as part of the MAC address assignment process.
1.2 I²C® Interface
The chip also features an I²C® interface. Use of the I²C port for device bring-up requires use of:
• I²C/Parallel interface adapter.
• Personal Computer
• CID software
• CobraNet Discovery Software
The software noted above is bundled with this document and can also be downloaded from the Cirrus Logic
web site. The interface adapter can be constructed from th e schematic included in this docu ment or can be
supplied by Cirrus Logic to qualified manufacturers.
Details on using the I²C interface and support software (CID) are provided in the “ I²C Interface and Software”
section.
Use of the I²C interface to load firmware is a two-step process. CID is used to load and run a base version
of firmware in volatile RAM. Once running from RAM and operational on the network, either CobraNet Discovery or the Python manufacturing script must be used to permanently load the FLASH memory with the
most current firmware version.
http://www.cirrus.com
Copyright © Cirrus Logic, Inc. 2008
(All Rights Reserved)
NOVEMBER '08
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2. HARDWARE DIAGNOSTICS
The standard firmware includes a boot-up routine that performs a Power On Se lf Test (POST). POST tests internal
memory, FLASH memory, the Ethernet controller, and audio clock circuitry. POST can discover and help diagnose
many hardware design errors.
When booting from pre-programmed FLASH, POST errors are reported through blinking indicators on the Ethernet
connectors. For detailed information on POST error r eporting, see the Error Reporting section in the CobraNet Pro-
grammer's Reference Manual.
When booting from the I²C interface, POST errors are reported at the CID command line as descri bed in the “POST
Results” section on page 4.
3. I²C INTERFACE AND SOFTWARE
The I²C interface hardware connects between a standard bidirectional parallel printer port on a PC and the target
system.
3.1 Software Installation
To install the software:
1. Unzip the contents of the software archive bundled with this document (CID_DIstribution.zip) to an empty directory.
2. Open a command prompt window and change to the directory containing the software.
3. Run 'port95nt' to install the parallel port I/O driver.
3.2 Connecting the Target System
The I²C adaptor connects to a PC parallel printer por t with a straight-through male-fem ale 25-pin cable. The
adaptor features a 10-pin header on the tar get side. The first four pins connect from the adaptor to the ta rget.
Pin 1 is marked with a square pad and is the pin furthest towards the bottom in Figure 1.
Figure 1. I²C Adaptor (right) Connected to an Example Target System (CM-2, left)
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