ZL50408
Data Sheet
62
Zarlink Semiconductor Inc.
11.4.1.11
Collisions
Counts number of collision events detected.
Only a best estimate since collisions can only be detected while in transmit mode, but not while in receive mode.
Use ZL50408 counter “Collision”, C[25].
11.4.1.12
Packet Count for Different Size Groups
Six different size groups – one counter for each. Counts both good and bad packets.
Pkts64Octets
for any packet with size = 64 bytes.
Use ZL50408 counter “Frames with Length of 64 Bytes”, C[12].
Pkts65to127Octets
for any packet with size from 65 bytes to 127 bytes
Use ZL50408 counter “Frames with Length Between 65-127 Bytes”, C[14].
Pkts128to255Octets
or any packet with size from 128 bytes to 255 bytes
Use ZL50408 counter “Frames with Length Between 128-255 Bytes”, C[16].
Pkts256to511Octets
for any packet with size from 256 bytes to 511 bytes
Use ZL50408 counter “Frames with Length Between 256-511 Bytes”, C[17].
Pkts512to1023Octets
for any packet with size from 512 bytes to 1023 bytes
Use ZL50408 counter “Frames with Length Between 512-1023 Bytes”, C[18].
Pkts1024to1518Octets
for any packet with size from 1024 bytes to 1518 bytes
Use ZL50408 counter “Frames with Length Between 1024-1518 Bytes”, C[19].
Note: the ZL50408 will include frames up to max. frame size.
Note: the ZL50408 doesn’t include bad frames in the above counters.
11.5
Miscellaneous Counters
In addition to the statistics groups defined in previous sections, the ZL50408 has other statistics counters for its own
purposes.
1. Flow control – one counting the number of flow control frames received, C[9], and another counting the number
of flow control frames sent, C[3].
2. Frames sent – one for unicast frames sent, C[1], and one for non-unicast frames sent, C[4]. A broadcast or mul-
ticast frame qualifies as non-unicast.
3. A counter called “frame send fail”, C[2]. This keeps track of FIFO under-runs, late collisions, and collisions that
have occurred 16 times.
4. A counter called “filtering”, C[27]. This keeps track of all frames dropped due to queue congestion (i.e. egress
WRED).
Min. Frame Size
Max. Frame Size
Frame size:
any size