The "Scheduler: Protect: Parity error for tick table single port SRAM" message reports a transient hardware memory error.

This is a Troubleshooting Article for a PFE ASIC Syslog Event.

To view other documented syslog events related to XMCHIP, XLCHIP, MQCHIP, LUCHIP, EACHIP, and PECHIP, see KB31893 - Master Index of Articles for Troubleshooting PFE ASIC Syslog Events  [juniper.net].

When a "Scheduler: Protect: Parity error for tick table single port SRAM" event occurs, a message similar to the following is reported.Since this error is categorised as major, as an action the respective PFE has been disabled.

Log:-

Feb 14 00:24:12.107 Device : %PFE-6: fpc3 Error: /fpc/3/pfe/0/cm/0/XMCHIP(0)/0/XMCHIP_CMERROR_SCHED_PAR_PROTECT_FSET_REG_DETECTED_TK_TBL (0x702ef), severity: major, module: XMCHIP(0), type: SCHED_PROTECT: Detected: Parity error for Tick table single port SRAM 

Feb 14 00:24:12.235 Device alarmd[69022]: %DAEMON-4: Alarm set: FPC color=RED, class=CHASSIS, reason=FPC 3 Major Errors - XM Chip Error code: 0x702ef

Feb 14 00:24:12.235 Device chassisd[68457]: %DAEMON-3: FPC 3 sent action 0x44 that is not configured 0x2 

Feb 14 00:24:12.235 Device craftd[13776]: %DAEMON-4: Major alarm set, FPC 3 Major Errors - XM Chip Error code: 0x702ef

Feb 14 00:24:12.676 Device tnp.tftpd[64187]: %DAEMON-6-TFTPD_CONNECT_INFO: TFTP write from address 19 port 3 file /var/tmp/pfe_debug_info_NGMPC3

Feb 14 00:24:15.681 Device : %PFE-3: fpc3 XMCHIP(0): XMCHIP(0): Scheduler: Protect: Log Error 0x4, Log Address 0xa5e, Multiple Errors 0x4 

Feb 14 00:24:17.432 Device pccd: %USER-3: [53257] PCCD received message 'PCEP_MSG_KEEPALIVE' from libpcep

Feb 14 00:24:18.600 Device : %PFE-5: fpc3 PFE 0: 'PFE Disable' action performed. Bringing down ifd xe-3/0/0 852 

Feb 14 00:24:18.661 Device : %PFE-6: fpc3 XMCHIP(0): XMCHIP(0): XXLCE0: Port Alarms: Detected Ethernet MAC Remote Fault Delta Event for Port 1 (xe-3/0/0) 

Feb 14 00:24:18.708 Device rpd[68979]: %DAEMON-6: EVENT <UpDown> xe-3/0/0.32767 index 1025 <Broadcast Multicast> address #0 3c.94.d5.35.9.ef

Feb 14 00:24:18.715 Device kernel: %KERN-3: if_msg_ifd_cmd_tlv_decode ifd xe-3/0/0 #852 down with ASIC Error

Feb 14 00:24:18.715 Device kernel: %KERN-3: if_msg_ifd_cmd_tlv_decode ifd xe-3/0/1 #853 down with ASIC Error

Feb 14 00:24:18.715 Device kernel: %KERN-3: if_msg_ifd_cmd_tlv_decode ifd xe-3/1/0 #854 down with ASIC Error

Feb 14 00:24:18.715 Device kernel: %KERN-3: if_msg_ifd_cmd_tlv_decode ifd xe-3/1/1 #855 down with ASIC Error

The cause is due to a transient parity error detected in XMCHIP memory Scheduler block hardware. It is suggested to restart the FPC during a MW to clear the error and to re-enable the disabled PFE.

If error are seen after restart of FPC then damage is permanent and FPC needs to be replaced.