SPRZ580 December   2024 AM62D-Q1

 

  1.   1
  2. 1Usage Notes and Advisories Matrices
    1. 1.1 Devices Supported
  3. 2Silicon Usage Notes and Advisories
    1. 2.1 Silicon Usage Notes
      1.      i2351
      2.      i2372
    2. 2.2 Silicon Advisories
      1.      i2049
      2.      i2062
      3.      i2134
      4.      i2189
      5.      i2196
      6.      i2199
      7.      i2208
      8.      i2249
      9.      i2278
      10.      i2279
      11.      i2310
      12.      i2311
      13.      i2312
      14.      i2366
      15.      i2371
      16.      i2120
      17.      i2137
      18.      i2253
      19.      i2383
      20.      i2401
      21.      i2407
      22.      i2409
      23.      i2410
      24.      i2376
      25.      i2399
      26.      i2413
      27.      i2414
      28.      i2417
      29.      i2419
      30.      i2420
      31.      i2421
      32.      i2422
      33.      i2423
      34.      i2431
      35.      i2435
  4.   Trademarks
  5.   Revision History

i2401

CPSW: Host Timestamps Cause CPSW Port to Lock up

Details:

The CPSW offers two mechanisms for communicating packet ingress timestamp information to the host.

The first mechanism is via the CPTS Event FIFO which records timestamps when triggered by certain events. One such event is the reception of an Ethernet packet with a specified EtherType field. Most commonly this is used to capture ingress timestamps for PTP packets. With this mechanism the host must read the timestamp (from the CPTS FIFO) separately from the packet payload which is delivered via DMA. This mode is supported and is not affected by this errata.

The second mechanism is to enable receive timestamps for all packets, not just PTP packets. With this mechanism the timestamp is delivered alongside the packet payload via DMA. This second mechanism is the subject of this errata.

When the CPTS host timestamp is enabled, every packet to the internal CPSW port FIFO requires a timestamp from the CPTS. When the packet preamble is corrupted due to EMI or any other corruption mechanism a timestamp request may not be sent to the CPTS. In this case the CPTS will not produce the timestamp which causes a lockup condition in the CPSW port FIFO. When the CPTS host timestamp is disabled by clearing the tstamp_en bit in the CPTS_CONTROL register the lockup condition is prevented from occurring.

Workaround(s):

Ethernet to host timestamps must be disabled.

CPTS Event FIFO timestamping can be used instead of CPTS host timestamps.