6. Event Management > Event Clearing and Recovery
CPS-1848 User Manual
158
June 2, 2014
Formal Status
This document is confidential and is subject to an NDA.
Integrated Device Technology
6.4.6
Software Controlled Isolation Functions
The following isolation functions/events are invoked under software control:
• Packet received that references a disabled port and is dropped
• Packet received that references a port configured in port lockout and is dropped
• Discarded a non-maintenance packet to be transmitted
• Discarded a received non-maintenance packet
• Packet received that references no route and is dropped
These isolation functions enable software to prevent a CPS-1848 link partner from accessing all or part of the system, and to
ensure that unauthorized access to a CPS-1848 link partner cannot occur.
A port should be disabled if no link partner is ever expected to be present on the link (see
.PORT_DIS). A port should be placed in port-lockout if a new link partner may appear (see
.PORT_LOCKOUT).
INPUT_PORT_EN and OUTPUT_PORT_EN isolation should be used to enable configuration and limited communication with
a new link partner.
The “No Route” routing table value should be used to prevent one link partner from accessing another link partner, or to ensure
that no link partners attempt to use a specific destID.
6.5
Event Clearing and Recovery
After an event is detected and reported, the software entity that receives the report must perform any reconfiguration of the
system necessary to continue system operation. The software entity must also clear the event, and disable any isolation
function that was activated.
IDT recommends that once one event has been received, all outstanding events should be handled. Only one event usually
will be outstanding at any specific time. There are situations that can result in the detection of multiple events.
The following sections describe how to clear each event, and provide advice on the handling of each event.
6.5.1
Logical Layer Event Clearing and Handling
describes how to clear and handle logical layer events.
Packet filtering functionality can implement finer grained isolation of the link partner from the remainder
of the system (for more information, see
Table 60: Logical/Transport Layer Event Enable and Information Capture Summary
Event
Clearing The Event
Event Handling Discussion
Illegal transaction decode
Logical/Transport Layer Error
Detect CSR
This error could indicate a hardware/software failure in the
originating endpoint, or a highly unlikely transmission error.
Unsolicited response
Logical/Transport Layer Error
Detect CSR
Receipt of a maintenance response implies a routing error.
Check the routing for the destID latched in the
. There should be a timeout for a
maintenance request originated by the sourceID latched in this
same register.