High Performance Two Port 10/100 Managed Ethernet Switch with 32-Bit Non-PCI CPU Interface
Datasheet
SMSC LAN9312
233
Revision 1.4 (08-19-08)
DATASHEET
14.2.6.3
Port 0(Host MAC) Manual Flow Control Register (MANUAL_FC_MII)
This read/write register allows for the manual configuration of the switch Port 0(Host MAC) flow control.
This register also provides read back of the currently enabled flow control settings, whether set
manually or Auto-Negotiated. Refer to
Section 6.2.3, "Flow Control Enable Logic," on page 58
for
additional information.
Note:
The flow control values in the
Section 14.2.8.5, "Virtual PHY Auto-Negotiation Advertisement
Register (VPHY_AN_ADV)," on page 252
are not affected by the values of this register.
Offset:
1A8h
Size:
32 bits
BITS
DESCRIPTION
TYPE
DEFAULT
31:8
RESERVED
RO
-
7
Port 0 Hard-wired Flow Control (HW_FC_MII)
When set to “1”, the Host MACs RX FIFO level is connected to the switch
engine’s transmitter and the switch engines RX FIFO level is connected to
the Host MACs transmitter. This achieves lower latency flow control.
Note:
All other flow control methods must be disabled when using this
feature. (MANUAL_FC_MII should be set, TX_FC_MII,
RX_FC_MII, and BP_EN_MII should be cleared. FCANY, FCADD,
FCBRD, and FCMULT in the AFC_CFG register should be
cleared).
R/W
0b
6
Port 0 Backpressure Enable (BP_EN_MII)
This bit enables/disables the generation of half-duplex backpressure on
switch Port 0.
0: Disable backpressure
1: Enable backpressure
R/W
5
Port 0 Current Duplex (CUR_DUP_MII)
This bit indicates the actual duplex setting of the switch Port 0.
0: Full-Duplex
1: Half-Duplex
RO
4
Port 0 Current Receive Flow Control Enable (CUR_RX_FC_MII)
This bit indicates the actual receive flow setting of switch Port 0
0: Flow control receive is currently disabled
1: Flow control receive is currently enabled
RO
3
Port 0 Current Transmit Flow Control Enable (CUR_TX_FC_MII)
This bit indicates the actual transmit flow setting of switch Port 0.
0: Flow control transmit is currently disabled
1: Flow control transmit is currently enabled
RO
2
Port 0 Receive Flow Control Enable (RX_FC_MII)
When the MANUAL_FC_MII bit is set, or Virtual Auto-Negotiation is
disabled, this bit enables/disables the detection of full-duplex Pause packets
on switch Port 0.
0: Disable flow control receive
1: Enable flow control receive
R/W