SMSC LAN9312 - Manual (Page 355)

High Performance Two Port 10/100 Managed Ethernet Switch with 32-Bit Non-PCI CPU Interface
Datasheet
SMSC LAN9312 355 Revision 1.4 (08-19-08)
DATASHEET
14.5.2.34 Port x MAC Transmit Undersize Count Register (MAC_TX_UNDSZE_CNT_x)
This register provides a counter of undersized packets transmitted by the port. The counter is cleared
upon being read.
Register #: Port0: 045Ah Size: 32 bits
Port1: 085Ah
Port2: 0C5Ah
BITS DESCRIPTION TYPE DEFAULT
31:0 TX Undersize
Count of packets that have less than 64 bytes.
Note: This condition could occur when TX padding is disabled and a tag
is removed.
Note: This counter will stop at its maximum value of FFFF_FFFFh.
Minimum rollover time at 100Mbps is approximately 458 hours.
RC 00000000h