Xilinx LOGICORE UG144 - Manual (Page 81)

1-Gigabit Ethernet MAC v8.5 User Guide www.xilinx.com 81
UG144 April 24, 2009
Using the Optional Management Interface R
-- DISCONTINUED PRODUCT --
Flow Control Configuration
Table 8-6 lists the register contents for the Flow Control Configuration Word.
29 0 In-band FCS Enable When this bit is ‘1,’ the MAC
transmitter will expect the FCS field to be passed in by the
client. When this bit is ‘0,’ the MAC transmitter will
append padding as required, compute the FCS and
append it to the frame.
30 0 Jumbo Frame Enable When this bit is set to ‘1,’ the MAC
transmitter will send frames that are greater than the
specified IEEE 802.3-2005 maximum legal length. When
this bit is ‘0,’ the MAC will only send frames up to the
specified maximum.
31 0 Reset When set to ‘1,’ the transmitter will be reset. The bit
will then automatically revert to ‘0.’ This reset will also set
all of the transmitter configuration registers to their default
values.
Table 8-5: Transmitter Configuration Word (Continued)
Bit
Default
Value
Description
Table 8-6: Flow Control Configuration Word
Bit
Default
Value
Description
28-0 n/a Reserved
29 1 Flow Control Enable (RX) When this bit is ‘1,’ received
flow control frames will inhibit the transmitter operation.
When this bit is ‘0,’ received flow control frames will
always be passed up to the client.
30 1 Flow Control Enable (TX) When this bit is ‘1,’ asserting the
PAUSE_REQ signal will send a flow control frame out
from the transmitter. When this bit is ‘0,’ asserting the
PAUSE_REQ signal has no effect.
31 n/a Reserved