lan9221 Standard Microsystems Corp., lan9221 Datasheet - Page 93

• Manufacturer Part Number: lan9221
• Description: High-performance 16-bit Non-pci 10/100 Ethernet Controller With Variable Voltage I/o
• Manufacturer: Standard Microsystems Corp.

High-Performance 16-bit Non-PCI 10/100 Ethernet Controller with Variable Voltage I/O
Datasheet
SMSC LAN9221/LAN9221i
5.3.11
5.3.12
31-24
23-16
31-24
23-16
BITS
BITS
15-0
15-0
Reserved
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).
Reserved
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.
RX_FIFO_INF—Receive FIFO Information Register
This register contains the used space in the receive FIFOs of the LAN9221/LAN9221i Ethernet
Controller.
TX_FIFO_INF—Transmit FIFO Information Register
This register contains the free space in the transmit data FIFO and the used space in the transmit
status FIFO in the LAN9221/LAN9221i.
Offset:
Offset:
DESCRIPTION
DESCRIPTION
7Ch
80h
DATASHEET
93
Size:
Size:
32 bits
32 bits
TYPE
TYPE
RO
RO
RO
RO
RO
RO
Revision 2.6 (12-04-08)
DEFAULT
DEFAULT
0000h
1200h
00h
00h
-
-