LAN9500 Datasheet, PDF (36/213 Pages) SMSC Corporation – USB 2.0 to 10/100 Ethernet Controller Promiscuous mode

LAN950x
String Indices 1-5
TABLE 5-13: STRING DESCRIPTOR (INDICES 1-5)
Offset
Field
Size
(Bytes)
Default
Value
Loaded
from
EEPROM
Description
00h bLength
1
none
Yes
Size of the String Descriptor in bytes (4
bytes)
01h bDescriptorType
1
none
Yes
String Descriptor (0x03)
02h Unicode String
2*N
none
Yes
2 bytes per unicode character, no
trailing NULL.
Note 1: If there is no valid/enabled EEPROM, or if the corresponding String Length and offset in the EEPROM for a
give string index are zero, then that string does not exist, so any host attempt to read that string will return
stall in the Data Stage of the Control Transfer.
2: The device returns whatever bytes are in the designated EEPROM area for each of these strings it is the
responsibility of the EEPROM programmer to correctly set the bLength and bDescriptorType fields in the
descriptor consistent with the byte length specified in the corresponding EEPROM locations.
5.3.1.7 Statistics
The CTL tracks the statistics listed in Table 5-14. The statistics are read via the Get Statistics Vendor Command.
Note: (LAN9500/LAN9500i ONLY):
The counters do not rollover and they are cleared on read.
(LAN9500A/LAN9500Ai ONLY):
The counters are snapshot when fulfilling the command request. The statistics counters rollover.
Error conditions are indicated via the RX Status Word, Table 5-40 on page 45, or the TX Status Word, Table 5-44 on
page 50.
TABLE 5-14: STATISTICS COUNTERS
Name
Description
RX Good Frames
RX CRC Errors
RX Runt Frame Errors
RX Alignment Errors
RX Frame Too Long Error
RX Later Collision Error
RX Bad Frames
RX FIFO Dropped Frames
Number of good RX frames received. Includes frames dropped by the
FCT.
Number of RX frames received with CRC-32 errors.
Note: A CRC error is indicated when the CRC error flag is set and
the dribbling bit flag is not set.
Number of RX frames received with a length of less than 64 bytes and
a CRC error.
Number of RX frames received with alignment errors.
Note: An alignment error is indicated by the presence of the CRC
error flag is set and the dribbling bit flag is set.
Number of RX frames received with a length greater than the
programmed maximum Ethernet frame size.
Number of RX frames received where a late collision has occurred.
Total number of errored Ethernet frames received. This counter does
not include RX FIFO Dropped Frames.
Number of RX frames dropped by the FCT due to insufficient room in
the RX FIFO.
Note:
If an RX FIFO dropped frame has an Ethernet error, i.e CRC
error, it must only be counted by the RX FIFO Dropped
Frames counters.
Size
(Bits)
32
20
20
20
20
20
20
20
DS00001875A-page 36
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