Cirrus Logic AN334 - Manual (Page 2)

2 AN334REV1
AN334
2. HARDWARE DIAGNOSTICS
The standard firmware includes a boot-up routine that performs a Power On Self 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 reporting, 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 described 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 emp-
ty 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 port with a straight-through male-female 25-pin cable. The
adaptor features a 10-pin header on the target side. The first four pins connect from the adaptor to the target.
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)