2. Serial RapidIO Interface > Loss of Lane Synchronization
64
Tsi578 User Manual
June 6, 2016
Integrated Device Technology
www.idt.com
2.10.1
Dead Link Timer
When a LOLS event occurs, the loss of communication can continue for an extended length of time.
For example, there may be an uncontrolled extraction of the link partner, and a hardware fault on the
link partner. Packets continue to be directed to the non-functional (dead) link, but are not able to make
forward progress. As a result, this may eventually block every traffic path in the system.
To enable systems to robustly deal with dead links, the Tsi578 has a “dead link timer” feature. This is a
proprietary function that is outside of the RapidIO specification. The DLT_EN and DLT_THRESH
fields in the
“SRIO MAC x Digital Loopback and Clock Selection Register”
enable/disable the dead
link timer and specify the duration of the dead link timer. There is one DLT for four ports (Ports N,
N+1, N+8 and N+9, where N = 0, 2, 4, 6). The dead link timer can be disabled by setting DLT_EN to 0.
When the dead link timer is enabled (in the DLT_EN bit in the
“SRIO MAC x Digital Loopback and
) and a link failure causes the timer to expire, it is reported in the PORT_ERR
bit in the
“RapidIO Port x Error and Status CSR”
. When the PORT_ERR bit is set, and port-writes are
enabled, a port-write is generated.
If the dead link timer expires, which the link is no longer able to transmit or receive, then the port starts
removing the impact of the dead link partner from the system. The port drops all packets in its transmit
buffers. Any new packets that are transferred to the port from the ISF are accepted and dropped.
Packets received by the port from its link partner can still be forwarded to the ISF.
2.10.2
Lane Sync Timer
Supplementary to the Dead Link Timer is the Lane Sync Timer (LST). There is one LST for each lane
of the Tsi578 MAC. The LST for a lane starts when lane sync is lost after a link has successfully
initialized. When the LST expires for any lane on a port, the PORT_ERR bit is set in the
.
The LST is a constant 0xFFFFF symbol periods for a link. The timeouts for different lane speeds are
given in the following table:
Note that only the PORT_ERR status bit indicates that an LST has expired.
The dead link timer register fields affect the RapidIO ports (Ports N and N+1) sharing the
Tsi578 MAC.
When the Tsi578 MAC is operating in two 1x mode and the LST expires on the odd port, the
even port will detect a spurious PORT_ERR.
Lane Speed
Timeout (nsec)
1.25
8,388,600
2.5
4,194,300
3.125
3,355,440
Содержание Tsi578
Страница 1: ...IDT Tsi578 Serial RapidIO Switch User Manual June 6 2016 Titl ...
Страница 20: ...About this Document 20 Tsi578 User Manual June 6 2016 Integrated Device Technology www idt com ...
Страница 102: ...4 Internal Switching Fabric Packet Queuing 102 Tsi578 User Manual June 6 2016 Integrated Device Technology www idt com ...
Страница 228: ...11 Signals Pinlist and Ballmap 228 Tsi578 User Manual June 6 2016 Integrated Device Technology www idt com ...
Страница 504: ...B Clocking P_CLK Programming 504 Tsi578 User Manual June 6 2016 Integrated Device Technology www idt com ...
Страница 526: ...Index 526 Tsi578 User Manual June 6 2016 Integrated Device Technology www idt com ...