Intel PCI User Manual
296
Software Developer’s Manual
Register Descriptions
13.4.22
Receive Control Register
RCTL (00100h; R/W)
This register controls all Ethernet controller receiver functions.
Table 13-67. RCTL Register Bit Description
TXD_LOW
15
X
Clears the mask for Transmit Descriptor Low Threshold hit (not
applicable to the 82544GC/EI).
applicable to the 82544GC/EI).
SRPD
16
X
Clears mask for Small Receive Packet Detect Interrupt (not
applicable to the 82544GC/EI).
applicable to the 82544GC/EI).
Reserved
31:17
X
Reserved
Should be written with 1b to ensure future compatibility.
Should be written with 1b to ensure future compatibility.
Field
Bit(s)
Initial
Value
Value
Description
31
27 26
0
Reserved
Receive Control Bits
Field
Bit(s)
Initial
Value
Value
Description
Reserved
0
0b
Reserved
Write to 0b for future compatibility.
Write to 0b for future compatibility.
EN
1
0b
Receiver Enable
The receiver is enabled when this bit is 1b. Writing this bit to 0b
stops reception after receipt of any in-progress packets. Data
remains in the receive FIFO until the device is re–enabled.
Disabling or re-enabling the receiver does not reinitialize the packet
filter logic that demarcates packet start and end locations in the
FIFO; Therefore the receiver must be reset before re-enabling it.
The receiver is enabled when this bit is 1b. Writing this bit to 0b
stops reception after receipt of any in-progress packets. Data
remains in the receive FIFO until the device is re–enabled.
Disabling or re-enabling the receiver does not reinitialize the packet
filter logic that demarcates packet start and end locations in the
FIFO; Therefore the receiver must be reset before re-enabling it.
SBP
2
0b
Store Bad Packets
0b = do not store.
1b = store bad packets.
When set, the Ethernet controller stores bad packets (CRC error,
symbol error, sequence error, length error, alignment error, short
packets or where carrier extension or RX_ERR errors) that pass the
filter function in host memory. When the Ethernet controller is in
promiscuous mode, and SBP is set, it might possibly store all
packets.
0b = do not store.
1b = store bad packets.
When set, the Ethernet controller stores bad packets (CRC error,
symbol error, sequence error, length error, alignment error, short
packets or where carrier extension or RX_ERR errors) that pass the
filter function in host memory. When the Ethernet controller is in
promiscuous mode, and SBP is set, it might possibly store all
packets.
UPE
3
0b
Unicast Promiscuous Enabled
0b = Disabled.
1b = Enabled.
When set, passes without filtering out all received unicast packets.
Otherwise, the Ethernet controller accepts or rejects unicast
packets based on the received packet destination address match
with 1 of the 16 stored addresses.
0b = Disabled.
1b = Enabled.
When set, passes without filtering out all received unicast packets.
Otherwise, the Ethernet controller accepts or rejects unicast
packets based on the received packet destination address match
with 1 of the 16 stored addresses.