Author: Matthew Hallberg, Storage Protocol Specialist
LeCroy Protocol Solutions Group
This article takes a close look at a specific problem which might occur during the development phase of a new SAS-2 product. Although one issue is dealt with here, the approach and techniques utilized can be generalized to the many different issues that might be encountered while developing and debugging new products.
The Problem: Incomplete READ(10) Commands
A problem has been reported during testing that appears to be associated with READ(10) commands. In order to troubleshoot this problem, the user first needs to understand the issue, then develop a means to replicate the problem, and finally to develop a test scenario to ensure the problem is fixed and does not reoccur.
Understanding protocol issues starts with the use of a protocol analyzer. Replication of the problem and establishment of a standard test requires the use of a device or host emulator. For this example, using a test tool is recommended that has the ability to act as both a protocol analyzer and an emulator which also fully supports the SAS-2 specification.