6. Event Notification > Interrupt Notifications
136
Tsi578 User Manual
June 6, 2016
Integrated Device Technology
www.idt.com
6.6.4
Port-writes and Hot Insertion/Hot Extraction Notification
Port-write requests are used to support hot insertion/extraction notification. For more information, refer
to Hot Insertion and Hot Extraction (see
“Hot Insertion and Hot Extraction” on page 59
The sending device sets the PORT_W_PEND status bit in the
“RapidIO Port x Error and Status CSR”
. Software indicates that it has seen the port-write operation by clearing the
PORT_W_PEND bit. In order to clear the PORT_W_PEND bit, software must first clear the
Port x Error Detect CSR” on page 294
.
6.6.5
Port-writes and Multicast
Port-writes can be multicast to multiple output links, depending on the destinationID of the port-write.
Using the multicast feature improves the likelihood of delivery of port-writes for link failures.
If a port generates a port-write packet, and the destinationID of the port-write packet that is contained
in the
“RapidIO Port-Write Target Device ID CSR”
is also contained in a multicast group, the
port-write will be routed to the multicast engine. The multicast engine does not distinguish between
port-write packets and other types of packets. The multicast engine will multicast the port-write packet
to ports according to the mask associated with destinationID of a multicast group. However, in
respecting the RapidIO Multicast specification, if the originating port is contained in the multicast
mask, the multicast engine will remove the source port from the mask list preventing the port-write
packet from being transmitted out of the port that originated the port-write packet.
6.7
Interrupt Notifications
In the Tsi578 interrupts are hierarchical, which allows software to determine the cause of the interrupt
with minimum register access.
illustrates the interrupt hierarchy within the Tsi578 RapidIO ports.
If a blocked or failed port becomes unblocked port-writes may be delivered late.
System designers must decide upon a maximum rate of interrupt notifications, and set the
error thresholds appropriately.