Teledyne LeCroy SAS_SATA InFusion - Users Manual - Manual (Page 49)

SAS InFusion User Manual Version 2.0
LeCroy Corporation
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As with Global Rules, the menu-driven interface guides you in building a sequence.
Some of the prompts are different, however, because you now are encapsulating groups
of events and actions as distinct states. Recall that a state is a combination of events and
actions at a specific point in time. If the event or combined event defined by a state
occurs, the corresponding action or set of actions follows.
Figure 35 Global Rules and Sequence Areas of a Scenario
SAS InFusion hardware provides the capacity to have up to two sequences co-existing
in a scenario in addition to the Global Rules. Recall that both the Global Rules and any
sequences are active at all times. Each is a separate "state machine," having the
behavior of a particular test state at any point in time. Because the Global Rules has the
capacity for only one state, you can view it as a "degenerative state machine."
Multi-Link
Testing
SAS Infusion hardware supports testing of SAS wide-link configurations. Wide-link uses
multiple physical links to aggregate traffic from up to four separate lines into one logical
link.
Each SAS InFusion box has two BNC connectors on its rear panel that allow it to connect
to other SAS InFusion boxes in a daisy-chain. One connector is for signal input, the other
for signal output.
The BNC connectivity allows you develop wide-link test schemes. In such schemes, four
boxes are connected in a daisy-chain, with the BNC output on an upstream box linked to
the BNC input on its downstream neighbor.
A separate scenario runs on each box, but the scenarios interact through trigger signals
exchanged via their BNC ports. For example, you can set the first box in the daisy-chain
to send a trigger downstream when it detects a specific line condition. The trigger can
cause a state change in the scenario running on the downstream box. That box, in turn,
can cause a state change in the scenario running on its neighbor.
Each of the four boxes is monitoring/modifying its own line, but there is a synergy
between the four by way of the BNC daisy-chain. In this fashion, you can use a SAS
InFusion daisy-chain to coordinate error injection across multiple SAS or SATA physical
links.