LAN9220 Datasheet, PDF (92/150 Pages) SMSC Corporation – 16-bit Non-PCI Small Form Factor 10/100 Ethernet Controller with Variable Voltage I/O & HP Auto-MDIX Support

5.3.11
16-bit Non-PCI Small Form Factor 10/100 Ethernet Controller with Variable Voltage I/O & HP Auto-MDIX Support
Datasheet
RX_FIFO_INF—Receive FIFO Information Register
Offset:
7Ch
Size:
32 bits
This register contains the used space in the receive FIFOs of the LAN9220 Ethernet Controller.
BITS
DESCRIPTION
31-24 Reserved
23-16
15-0
RX Status FIFO Used Space (RXSUSED). Indicates the amount of space
in DWORDs, used in the RX Status FIFO.
RX Data FIFO Used Space (RXDUSED).). Reads the amount of space in
bytes, used in the RX data FIFO. For each receive frame, this field is
incremented by the length of the receive data rounded up to the nearest
DWORD (if the payload does not end on a DWORD boundary).
TYPE
RO
RO
RO
DEFAULT
-
00h
0000h
5.3.12 TX_FIFO_INF—Transmit FIFO Information Register
Offset:
80h
Size:
32 bits
This register contains the free space in the transmit data FIFO and the used space in the transmit
status FIFO in the LAN9220.
BITS
DESCRIPTION
31-24 Reserved
23-16
15-0
TX Status FIFO Used Space (TXSUSED). Indicates the amount of space
in DWORDS used in the TX Status FIFO.
TX Data FIFO Free Space (TDFREE). Reads the amount of space in bytes,
available in the TX data FIFO. The application should never write more data
than is available, as indicated by this value.
TYPE
RO
RO
RO
DEFAULT
-
00h
1200h
Revision 2.6 (12-04-08)
92
DATASHEET
SMSC LAN9220